Question

1/4 l4x+7l = 8x + 16 Solve for this equation. Now the answer is -71/36 but, I don't know how they solved to get that answer. Can someone help?

Answer 1

@monokerous any idea how to solve it?

Answer 2

change the absolute value to parens and solve.
also solve
-(1/4) (4x+7) = 8x+16

check both solutions to make sure they are allowed.

Answer 3

@phi check both solutions? what do you mean?

Answer 4

For absolute values, there are always two solutions that you get.

Answer 5

I know so how would i set up both equations to get my 2 solutions?

Answer 6

I'm trying to look for a useful site (as a refresher or something) as I've only ever learnt absolute values once, briefly. lol. Sorry.

Answer 7

I tried doing that but, i didn't have much luck it doesnt give an example like this

Answer 8

Agreed.

Answer 9

the first equation: if the stuff inside the abs value is positive, you can drop the | |:
(1/4) ( 4x+7)= 8x+16
solve for x

if the stuff inside is negative, then we can say
(-1/4)(4x+7)= 8x+16

solve for x

the solution may be invalid for one of the x. Try it.

Answer 10

Ok, I will solve it. Thanks I will let you know what i get

Answer 11

would i distribute (1/4) with (4x +7)??

Answer 12

1/4 l4x+7l = 8x + 16 or
| 4x +7| =4(8x+16)

you can get an invalid x if the right side is negative with that x. (because the left side, with the abs value, can never be negative)

Answer 13

to solve
1/4 (4x+7)= 8x+16

I would multiply both sides by 4 (who likes fractions!)
4x+7= 4*8x+4*16
collect terms and simplify

Answer 14

Ok thank you so much!