How do you solve |-5x + -2| = 12?

1 Answer
Aug 1, 2016

x=-14/5 and x=2

Explanation:

We are given abs(-5x+ -2)=12. To solve this, we should first simplify the expression inside the absolute value bars, like this -5x-2. Okay... that's pretty much it. Now we move on to the next step.

Absolute value bars make whatever is within them positive. That means that we need to find two vaues for x: one positive and one negative.

So, instead of one equation, we have two. abs(-5x-2)=12 becomes -5x-2=12 and -5x-2=-12. Now we just solve for x.

-5x-2=12 color(white)(.......................) -5x-2=-12
color(white)(.....)+2color(white)()+2 color(white)(.......................) color(white)(.........)+2color(white)(.......)+2

-5x=14 color(white)(...............................) -5x=-10
color(white)(1)/-5color(white)(...)color(white)(1)/-5 color(white)(...............................) color(white)(1)/-5color(white)(.......)color(white)(1)/-5

x=-14/5 color(white)(...............................) x=2

So, x is -14/5 or 2 . If we want to, we can double check our answers by graphing the equation and see the x-intercepts.

graph{abs(-5x-2)-12=y}

We got it right!! Great job.