Question

Solve for x: |2x + 6| - 4 = 20

a. x = 9 and x = 11
b. x = -9 and x = 15
c. x = 9 and x = - 15
d. no solution

okay I got x = 9 but i dont know what the other number is?

Answer 1

you got |2x + 6| = 24 right?

then you got 2x + 6 = 24 ---> x = 9

Answer 2

since |2x + 6| = 24, it breaks down into these two equations


2x + 6 = 24

OR

2x + 6 = -24

Answer 3

because |x| = k breaks down into x = k or x = -k (k is positive)

example: |x| = 7 ---> x = 7 or x = -7