Examples with solutions for Equations with Absolute Values: Solving the problem

Exercise #1

∣x∣=3 \left|x\right|=3

Step-by-Step Solution

The equation is ∣x∣=3 \left|x\right|=3 , which implies that x x can be 3 or -3. Hence, the solutions are x=3 x=3 and x=−3 x=-3 .

Answer

Answers a + c

Exercise #2

∣x∣=6 \left|x\right|=6

Step-by-Step Solution

The equation is ∣x∣=6 \left|x\right|=6 , so x x could be 6 or -6. Therefore, the solutions are x=6 x=6 and x=−6 x=-6 .

Answer

Answers b + c

Exercise #3

∣−x∣=10 \left|-x\right|=10

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Use the definition of absolute value to create equations.
  • Step 2: Solve each equation to find possible values of x x .
  • Step 3: Check the solutions against the original problem.

Now, let's work through each step:
Step 1: The equation is given as ∣−x∣=10 \left| -x \right| = 10 . According to the definition of absolute value:

  • Case 1: −x=10-x = 10
  • Case 2: −x=−10-x = -10

Step 2: Solve each case:
In Case 1, we have:

  • −x=10-x = 10
    This implies x=−10 x = -10 .

In Case 2, we have:

  • −x=−10-x = -10
    This implies x=10 x = 10 .

Step 3: Therefore, the possible solutions are x=−10 x = -10 and x=10 x = 10 , which satisfy the equation independently.

The solution to the problem is:

x=−10 x = -10 , x=10 x = 10

Answer

x=−10 x=-10 , x=10 x=10

Exercise #4

−∣x∣=15 -\left|x\right|=15

Step-by-Step Solution

Let's solve the equation −∣x∣=15 -\left|x\right|=15 . Since the expression inside the absolute value can be either positive or negative, we consider two scenarios:

1. −x=15 -x = 15 : This implies x=−15 x = -15 .

2. −(−x)=15 -(-x) = 15 : This simplifies to x=15 x = 15 .

Thus, the solutions are x=−15 x = -15 and x=15 x = 15 .

Answer

x=−15 x=-15 , x=15 x=15

Exercise #5

∣−4x∣=12 \left|-4x\right|=12

Step-by-Step Solution

To solve the equation ∣−4x∣=12 \left|-4x\right|=12 , we consider the definition of absolute value:

1. The expression inside the absolute value can be either positive or negative, but its absolute value is always positive.

2. Therefore, we set up two equations to solve:

−4x=12 -4x = 12 and −4x=−12 -4x = -12

3. Solving the first equation:

−4x=12 -4x = 12

4. Divide both sides by -4:

x=−3 x = -3

5. Solving the second equation:

−4x=−12 -4x = -12

6. Divide both sides by -4:

x=3 x = 3

7. Therefore, the solution is:

x=−3 x=-3 , x=3 x=3

Answer

x=−3 x=-3 , x=3 x=3

Exercise #6

∣x∣=4 \left|x\right|=4

Step-by-Step Solution

The equation is ∣x∣=4 \left|x\right|=4 . This means that the value of x x can be either 4 or -4. Thus, the solutions are x=4 x=4 and x=−4 x=-4 .

Answer

Answers a + c

Exercise #7

∣x∣=5 \left|x\right|=5

Video Solution

Step-by-Step Solution

To solve the equation ∣x∣=5\left| x \right| = 5, consider what absolute value means. The absolute value ∣x∣\left| x \right| represents the distance between xx and 0 on the number line, meaning it’s always non-negative.

When solving ∣x∣=5\left| x \right| = 5, we find the values of xx that are 5 units away from 0. Hence, the absolute value equation ∣x∣=5\left| x \right| = 5 results in two possible equations:

  • x=5x = 5
  • x=−5x = -5

So, the solutions to the absolute value equation ∣x∣=5\left| x \right| = 5 are x=5x = 5 and x=−5x = -5.

Let's compare these solutions to the answer choices provided:

  • Choice 1: x=5x = 5 matches one solution.
  • Choice 2: x=−5x = -5 matches the other solution.
  • Choice 4: "Answers a + b" suggests both are correct, which is indeed the case.

Thus, the choice that correctly represents the solutions to the equation ∣x∣=5\left| x \right| = 5 is "Answers a + b".

Therefore, the correct answer is:

Answers a + b

Answer

Answers a + b

Exercise #8

∣−3x∣=15 \left|-3x\right|=15

Step-by-Step Solution

To solve ∣−3x∣=15 \left|-3x\right|=15 , we consider both potential cases stemming from the absolute value:

1) −3x=15-3x=15:

Divide both sides by −3-3 to get x=−5x=-5.

2) −3x=−15-3x=-15:

Divide both sides by −3-3 to get x=5x=5.

Thus, the solutions are x=−5 x=-5 and x=5 x=5.

Answer

x=−5 x=-5 , x=5 x=5

Exercise #9

∣x∣=7 \left|x\right|=7

Step-by-Step Solution

The equation is ∣x∣=7 \left|x\right|=7 , which means that the absolute value of x x is 7. Therefore, x x could be 7 or -7. Thus, the solutions are x=7 x=7 and x=−7 x=-7 .

Answer

x=−7,x=7 x=-7, x=7

Exercise #10

∣3x∣=21 \left|3x\right|=21

Step-by-Step Solution

To solve the equation ∣3x∣=21 \left|3x\right|=21 , we consider the definition of absolute value:

1. The expression inside the absolute value can be either positive or negative, but its absolute value is always positive.

2. Therefore, we set up two equations to solve:

3x=21 3x = 21 and 3x=−21 3x = -21

3. Solving the first equation:

3x=21 3x = 21

4. Divide both sides by 3:

x=7 x = 7

5. Solving the second equation:

3x=−21 3x = -21

6. Divide both sides by 3:

x=−7 x = -7

7. Therefore, the solution is:

x=−7 x=-7 , x=7 x=7

Answer

x=−7 x=-7 , x=7 x=7

Exercise #11

∣−2x∣=16 \left|-2x\right|=16

Step-by-Step Solution

To solve the equation ∣−2x∣=16 \left|-2x\right|=16 , we consider the definition of absolute value:

1. The expression inside the absolute value can be either positive or negative, but its absolute value is always positive.

2. Therefore, we set up two equations to solve:

−2x=16 -2x = 16 and −2x=−16 -2x = -16

3. Solving the first equation:

−2x=16 -2x = 16

4. Divide both sides by -2:

x=−8 x = -8

5. Solving the second equation:

−2x=−16 -2x = -16

6. Divide both sides by -2:

x=8 x = 8

7. Therefore, the solution is:

x=−8 x=-8 , x=8 x=8

Answer

x=−8 x=-8 , x=8 x=8

Exercise #12

−∣x∣=8 -\left|x\right|=8

Step-by-Step Solution

Let's solve the equation −∣x∣=8 -\left|x\right|=8 . The expression inside the absolute value can take two forms:

1. −x=8 -x = 8 : This gives x=−8 x = -8 .

2. −(−x)=8 -(-x) = 8 : This simplifies to x=8 x = 8 .

Therefore, the solutions are x=−8 x = -8 and x=8 x = 8 .

Answer

x=−8 x=-8 , x=8 x=8

Exercise #13

∣a−2∣=6 \left| a - 2 \right| = 6

Step-by-Step Solution

To solve ∣a−2∣=6 \left| a - 2 \right| = 6 , consider the cases:

1. a−2=6 a - 2 = 6 leads to a=8 a = 8

2. a−2=−6 a - 2 = -6 leads to a=−4 a = -4

Thus, the solutions are a=8 a = 8 and a=−4 a = -4 .

Answer

a=8 a = 8 , a=−4 a = -4

Exercise #14

∣5−x∣=7 |5 - x| = 7

Step-by-Step Solution

To solve this problem, we'll use the absolute value property, which splits the equation into two separate cases:

  • Case 1: Solve 5−x=7 5 - x = 7

Subtract 5 from both sides:

5−x−5=7−5 5 - x - 5 = 7 - 5

Which simplifies to:

−x=2-x = 2

Multiplying both sides by -1 gives:

x=−2x = -2

  • Case 2: Solve 5−x=−7 5 - x = -7

Subtract 5 from both sides:

5−x−5=−7−5 5 - x - 5 = -7 - 5

Which simplifies to:

−x=−12-x = -12

Multiplying both sides by -1 gives:

x=12x = 12

Thus, the solutions are x=−2 x = -2 and x=12 x = 12 . Now let's verify against the available choices. We can see that:

  1. x = 0
  2. x = -2
  3. x = 12
  4. Answers b + c (i.e., x = -2 and x = 12)

This confirms that the correct choice is "Answers b + c".

Therefore, the correct answer is Answers b + c.

Answer

Answers b + c

Exercise #15

∣x−10∣=0 \left|x-10\right|=0

Video Solution

Step-by-Step Solution

To solve the problem ∣x−10∣=0\left|x-10\right|=0, we use this logical reasoning:

  • Step 1: Recognize that the absolute value expression equals zero.
    The property of absolute values states that for ∣A∣=0\left|A\right|=0, AA must equal zero.
  • Step 2: Apply this principle to the given equation.
    Given ∣x−10∣=0\left|x-10\right|=0, it follows that x−10=0x-10=0.
  • Step 3: Solve for xx.
    Rearrange the equation x−10=0x - 10 = 0 to find x=10x = 10.

The solution to the equation ∣x−10∣=0\left|x-10\right|=0 is therefore x=10 x = 10 .

Answer

x=10 x=10

Exercise #16

∣x−3∣=4 \left|x-3\right|=4

Video Solution

Step-by-Step Solution

To solve the equation ∣x−3∣=4 |x - 3| = 4 , follow these steps:

  • Step 1: Understand that ∣x−3∣=4 |x - 3| = 4 means x−3 x - 3 can be either 4 or -4.
  • Step 2: Set up two separate equations:
    • Equation 1: x−3=4 x - 3 = 4
    • Equation 2: x−3=−4 x - 3 = -4
  • Step 3: Solve each equation for x x .
  • Let's solve Equation 1:
    x−3=4 x - 3 = 4
    Add 3 to both sides:
    x=4+3 x = 4 + 3
    x=7 x = 7

    Now, solve Equation 2:
    x−3=−4 x - 3 = -4
    Add 3 to both sides:
    x=−4+3 x = -4 + 3
    x=−1 x = -1

    Therefore, the solutions to the equation ∣x−3∣=4 |x - 3| = 4 are x=7 x = 7 and x=−1 x = -1 .

    Checking the given choices, the correct answer is:
    x=−1 x = -1 , x=7 x = 7 , which matches choice 1.

Answer

x=−1 x=-1 , x=7 x=7

Exercise #17

∣x+1∣=5 \left|x+1\right|=5

Video Solution

Step-by-Step Solution

To solve the absolute value equation ∣x+1∣=5 |x + 1| = 5 , we follow these steps:

  • Step 1: Understand that the equation ∣x+1∣=5 |x + 1| = 5 means the expression inside the absolute value, x+1 x + 1 , is equal to 5 or -5.
  • Step 2: Set up two separate equations:
    • Equation 1: x+1=5 x + 1 = 5
    • Equation 2: x+1=−5 x + 1 = -5
  • Step 3: Solve each equation individually.
    • For Equation 1: Subtract 1 from both sides to get x=5−1=4 x = 5 - 1 = 4 .
    • For Equation 2: Subtract 1 from both sides to get x=−5−1=−6 x = -5 - 1 = -6 .

Thus, the solutions to the equation ∣x+1∣=5 |x + 1| = 5 are x=4 x = 4 and x=−6 x = -6 .

Therefore, the correct answer, considering the choices provided, is Answer a + b, which corresponds to choices 1 and 2.

Answer

Answers a + b

Exercise #18

∣x+2∣=4 \left|x+2\right|=4

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Set up two linear equations from the absolute value definition.
  • Step 2: Solve each equation for x x .

Now, let's work through each step:

Step 1: Consider the two cases from ∣x+2∣=4 \left|x + 2\right| = 4 .

  • First case: x+2=4 x + 2 = 4 .
  • Second case: x+2=−4 x + 2 = -4 .

Step 2: Solve the two equations:

For the first case:

x+2=4 x + 2 = 4

Subtract 2 from both sides:

x=4−2 x = 4 - 2 x=2 x = 2

For the second case:

x+2=−4 x + 2 = -4

Subtract 2 from both sides:

x=−4−2 x = -4 - 2 x=−6 x = -6

Therefore, the solutions to the equation ∣x+2∣=4 \left|x + 2\right| = 4 are:

x=−6 x = -6 and x=2 x = 2 .

The correct option is:

x=−6,x=2 x = -6, x = 2

Thus, the solution to the problem is:

x=−6,x=2 x = -6, x = 2

Answer

x=−6 x=-6 , x=2 x=2

Exercise #19

∣y−3∣=7 \left| y - 3 \right| = 7

Step-by-Step Solution

To solve ∣y−3∣=7 \left| y - 3 \right| = 7 , we need to consider the two possible cases for the absolute value equation.

1. y−3=7 y - 3 = 7 leads to y=10 y = 10

2. y−3=−7 y - 3 = -7 leads to y=−4 y = -4

Thus, the solutions are y=10 y = 10 and y=−4 y = -4 .

Answer

y=10 y = 10 ,y=−4 y = -4

Exercise #20

∣z+4∣=12 \left| z + 4 \right| = 12

Step-by-Step Solution

To solve ∣z+4∣=12 \left| z + 4 \right| = 12 , consider the two cases:

1. z+4=12 z + 4 = 12 gives z=8 z = 8

2. z+4=−12 z + 4 = -12 gives z=−16 z = -16

Thus, the solutions are z=8 z = 8 and z=−16 z = -16 .

Answer

z=−16 z = -16 , z=8 z = 8