Examples with solutions for Solving Equations by using Addition/ Subtraction: Solving the problem

Exercise #1

92x×224 ⁣:4=64 92-x\times2-24\colon4=64

Calculate X.

Video Solution

Step-by-Step Solution

First, we solve the multiplication and division exercises, we will put them in parentheses to avoid confusion:

92(x×2)(24 ⁣:4)=64 92-(x\times2)-(24\colon4)=64

922x6=64 92-2x-6=64

Reduce:

862x=64 86-2x=64

Move the sides:

2x=6486 -2x=64-86

2x=22 -2x=-22

Divide by negative 2:

x=222 x=\frac{-22}{-2}

x=11 x=11

Answer

11

Exercise #2

2y1yy+4=8y 2y\cdot\frac{1}{y}-y+4=8y

y=? y=\text{?}

Video Solution

Step-by-Step Solution

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

  • Simplify the term 2y1y 2y \cdot \frac{1}{y}
  • Rearrange the equation to group similar terms
  • Solve for y y

Now, let's work through each step:

Step 1: Simplify the expression 2y1y 2y \cdot \frac{1}{y} .

The term 2y1y 2y \cdot \frac{1}{y} simplifies directly to 2 2 since y y in the numerator and denominator cancel each other out assuming y0 y \neq 0 . Therefore, the equation becomes:

2y+4=8y 2 - y + 4 = 8y

Step 2: Combine like terms on the left-hand side:

2+4=6 2 + 4 = 6 , so the equation now is 6y=8y 6 - y = 8y .

Step 3: Rearrange the equation to isolate y y on one side. Add y y to both sides to get rid of the negative y y :

6=8y+y 6 = 8y + y

This simplifies to:

6=9y 6 = 9y

Step 4: Solve for y y by dividing both sides by 9:

y=69 y = \frac{6}{9}

Simplify the fraction to get:

y=23 y = \frac{2}{3}

Therefore, the solution to the problem is 23 \frac{2}{3} .

Answer

23 \frac{2}{3}

Exercise #3

How much is Xequal to?

(3217)×4×9 ⁣:350 ⁣:x=170 (32-17)\times4\times9\colon3-50\colon x=170

Video Solution

Step-by-Step Solution

To solve forx x in the equation (3217)×4×9 ⁣:350 ⁣:x=170 (32 - 17) \times 4 \times 9 \colon 3 - 50 \colon x = 170 , we will follow the order of operations: parentheses, exponents, multiplication and division (from left to right), and addition and subtraction (from left to right).

Step 1: Evaluate the Parentheses
First, solve the expression inside the parentheses: 3217=15 32 - 17 = 15 .

Substitute back into the equation:
15×4×9 ⁣:350 ⁣:x=170 15 \times 4 \times 9 \colon 3 - 50 \colon x = 170 .

Step 2: Perform Multiplication and Division
Continue with the multiplication and division from left to right.

  • First, multiply15 15 and 4 4 :
    15×4=60 15 \times 4 = 60

  • Next, multiply 60 60 by 9 9 :
    60×9=540 60 \times 9 = 540

  • Then, divide 540 540 by3 3 :
    540 ⁣:3=180 540 \colon 3 = 180

  • Now, subtract 50x \frac{50}{x} from 180 180 :
    18050x=170 180 - \frac{50}{x} = 170

Step 3: Isolate x x
We isolatex x by adding 50x \frac{50}{x} to both sides of the equation:
180=170+50x 180 = 170 + \frac{50}{x}

Subtract 170 from both sides:
180170=50x 180 - 170 = \frac{50}{x}

This simplifies to:
10=50x 10 = \frac{50}{x}

Step 4: Solve forx x
To find x x , solve the equation10x=50 10x = 50 which is derived from multiplying both sides by x x :
x=5010 x = \frac{50}{10}

The value of x x is:
x=5 x = 5

The final answer is 5 5 .

Answer

5

Exercise #4

What is the number that should replace y?

2312×(5)+y ⁣:7+[214]=107 23-12\times(-5)+y\colon7+\lbrack21-4\rbrack=107

Video Solution

Step-by-Step Solution

We begin by solving the multiplication exercise:

12×(5)=60 12\times(-5)=-60

and subsequently the exercises within brackets:

214=17 21-4=17

We obtain the following:

23(60)+y:7+17=107 23-(-60)+y:7+17=107

Keep in mind that a negative times a negative becomes a positive:

23+60+y:7+17=107 23+60+y:7+17=107

Next we simplify and add:

23+60=83 23+60=83

83+17=100 83+17=100

We obtain the following calculation:

100+y:7=107 100+y:7=107

We then rearrange the sections:

y:7=107100 y:7=107-100

y7=7 \frac{y}{7}=7

Lastly we multiply by 7:

y=7×7=49 y=7\times7=49

Answer

49