Solving Absolute Value Equations: Finding x in |x+3|=|2x+6|

Question

x+3=2x+6 |x+3|=|2x+6|

Video Solution

Step-by-Step Solution

To solve the equation x+3=2x+6 |x+3| = |2x+6| , we need to consider the properties of absolute values and analyze the cases for different ranges of x x .

The equation x+3=2x+6 |x+3| = |2x+6| implies two possibilities based on absolute value properties:

  • x+3=2x+6 x+3 = 2x+6
  • x+3=(2x+6) x+3 = -(2x+6)

Let's solve each case:

Case 1: x+3=2x+6 x+3 = 2x+6

Simplify the equation:
x+3=2x+6 x + 3 = 2x + 6
Move x x to the other side:
3=x+6 3 = x + 6
Subtract 6 from both sides:
x=3 x = -3

Case 2: x+3=(2x+6) x+3 = -(2x+6)

Simplify the equation:
x+3=2x6 x+3 = -2x-6
Add 2x 2x to both sides:
3x+3=6 3x + 3 = -6
Subtract 3 from both sides:
3x=9 3x = -9
Divide both sides by 3:
x=3 x = -3

In both cases, we find that x=3 x = -3 . However, we need to verify if x=3 x = -3 satisfies the original equation:

Substitute x=3 x = -3 into the original equation:
x+3=2x+6 |x+3| = |2x+6|
3+3=2(3)+6 |-3+3| = |2(-3)+6|
0=6+6 |0| = |-6+6|
0=0 0 = 0

Therefore, x=3 x = -3 satisfies the equation. The solution to the problem is x=3 x = -3 .

In conclusion, the correct answer is x=3 x = -3 .

Answer

x=3 x=-3