What two inequalities would you use to solve the absolute value inequality |4x + 3| 2?

Question

What two inequalities would you use to solve the absolute value inequality |4x + 3| > 2?

igreen · Answer

We split it into two inequalities, the one it is now:

4x + 3  > 2

And we multiply -1 to all the terms inside the absolute inequality brackets.

igreen · Answer

-1 * 4x = ?
-1 * 3 = ?

igreen · Answer

What do you get?

anonymous · Answer

negative 3

igreen · Answer

Yes, and what's -1 * 4x?

anonymous · Answer

-4x

anonymous · Answer

these are my answer choices A. 4x + 3 > -2, 4x + 3 < 2 B. 4x + 3 < -2, 4x + 3 > 2 C. 4x + 3 > 2, 4x – 3 < -2 D. 4x + 3 > 2, 4x + 3 > -2

texaschic101 · Answer

4x + 3 > 2 

-(4x + 3) > 2 = -4x - 3 > 2 = 4x + 3 < -2

igreen · Answer

Yes, so we have:

-4x - 3 > 2 and 4x + 3 > 2

igreen · Answer

Which..isn't a choice..lol.

igreen · Answer

I guess you can divide -1 to both sides too

texaschic101 · Answer

found that out....you have to multiply by -1 and change inequality sign

igreen · Answer

You mean divide..since it's being multiplied :P

igreen · Answer

But either way we still switch the sign, since it's negative.

texaschic101 · Answer

you can still multiply by -1....either way will work