3|-4x+75|+9=144 HELP

Question

myininaya · Answer

3|-4x+75|=199-4
|-4x+75|=195/3
-4x+75=195/3    or -4x+75=-195/3

anonymous · Answer

Just solve for the absolute value part first, then break it into two different equations.

anonymous · Answer

Then solve each equation and the solution set is the union of the solutions for each equation.

anonymous · Answer

but the answer is suppose to be 30.. http://www.wolframalpha.com/input/?i=3 |-4x%2B75|%2B9%3D144 i don't know how they did it though

anonymous · Answer

LOL ^ LOVE YOU, but that is not the solution... it should be 15/2

myininaya · Answer

x=-5/2 and 70/2 is what I got let me check

myininaya · Answer

omg i cant read numbers i did it for 199 not 144 lol

anonymous · Answer

yeah 15/2 which is... 30

anonymous · Answer

loll

anonymous · Answer

how did you solve it though? can you take a picture of your work so i know how you do it?

anonymous · Answer

$$3|-4x+75| = 144-9$$
$$|-4x + 75| = 135/3$$
$-4x + 75 = 135/3 $            or    $-4x + 75 = -135/3 $ 
$-4x  = 135/3 - 225/3$       or    $-4x  = -135/3 -225/3$ 
$-4x  = -90/3$                   or    $-4x  = -360/3$ 
$x  = 30/4$       or    $x  = 120/4$ 
$x  = 7/2$         or    $x  = 30$

anonymous · Answer

Hrm. I missed something on the left equation.

myininaya · Answer

x=15/2 or x=30

myininaya · Answer

you reduced wrong

anonymous · Answer

Yeah I see.

anonymous · Answer

$$x = 30/4 = 15/2 \ne 7/2$$

myininaya · Answer

at least when you read 4s you didn't write 9s and when you read 9s you didn't write 4s

anonymous · Answer

True ;p