How do you solve |-5x + -2| + 3 = 11?

1 Answer
Jan 26, 2017

x=-2" or " x=6/5

Explanation:

Equations involving the color(blue)"absolute value" have 2 solutions.

Isolate the absolute value, noting that

-5x+ -2=-5x-2

subtract 3 from both sides.

|-5x-2|cancel(+3)cancel(-3)=11-3

rArr|-5x-2|=8

The 2 solutions are obtained by solving -5x-2=color(red)(+-)8

color(blue)"Solution 1"

-5x-2=8

add 2 to both sides.

-5xcancel(-2)cancel(+2)=8+2

rArr-5x=10rArrx=10/(-5)=-2

color(blue)"Solution 2"

-5x-2=-8

add 2 to both sides.

-5x=-8+2

rArr-5x=-6rArrx=(-6)/(-5)=6/5

color(blue)"As a check"

"left side "=|(-5xx-2)-2|+3=|8|+3=8+3=11 ✔︎

"left side "=|(-cancel(5)^1xx6/cancel(5)^1)-2|+3

=|-6-2|+3=|-8|+3=8+3=11 ✔︎