## anonymous one year ago Solve for x: |2x + 6| − 4 = 20 x = 9 and x = 11 x = −9 and x = 15 x = 9 and x = −15 No solution

1. bahrom7893

|2x+6| -4 + 4 = 20 + 4 |2x+6| = 24

2. bahrom7893

Which means that 2x+6 could be either positive or negative 24, because: |24| = 24 and |-24|=24, so: (2x+6) = 24 or -(2x+6) = 24

3. bahrom7893

2x + 6 = 24 2x = 24-6 = 18 x=9

4. Excalibur0126

It's C but bahrom7893 can explain it

5. bahrom7893

-(2x+6) = 24 2x+6 = -24 2x = -24-6 = -30 x = -30/2 = -15

6. anonymous

oooh ok i see thank you :) can u help me with one more?

7. anonymous

@bahrom7893

8. Hero

$$|2x + 6| = 24$$ $$\sqrt{(2x + 6)^2}= 24$$ $$(2x + 6)^2 = 24^2$$ $$4x^2 + 24x + 36 = 576$$ $$4x^2 + 24x - 540 = 0$$ $$4(x^2 + 6x - 135 = 0$$ $$x^2 + 6x - 135 = 0$$ $$x^2 + (15 - 9)x - 135 = 0$$ $$x^2 + 15x - 9x - 135 = 0$$ $$x(x + 15) - 9(x + 15)$$ $$(x + 15)(x - 9) = 0$$ $$x = \{-15, 9\}$$