PLEASE HELP ME!!!
Given the equation below, solve for y.

Question

PLEASE HELP ME!!!
Given the equation below, solve for y.

anonymous · Answer

z-4=$$z-4\frac{ y ^{2}+8z-48}{ z-4 }$$

anonymous · Answer

@Jhannybean  please help me

anonymous · Answer

@kohai  please can you help me??

danjs · Answer

you get anyqwhere?

anonymous · Answer

@DanJS  please help me

anonymous · Answer

is it going to be y=z-4?

danjs · Answer

you need to isolate y on one side and it will = something in terms of all the other stuff, x

danjs · Answer

I would multiply both sides of the thing by (z-4) first

anonymous · Answer

y=z-8
is this the answer?

danjs · Answer

should that be a  +8y  instead of the +8z you typed?

anonymous · Answer

its a multiple choice question
is my answer right?

danjs · Answer

|dw:1443160932457:dw|

anonymous · Answer

its 8z

danjs · Answer

ok, just checking, that makes it easier, asking because a y would be a factorable numorator.

danjs · Answer

multiply both sides by (z-4)

(z - 4)*(z-4) = y^2 + 8z - 48

danjs · Answer

expand 

z^2 - 8z + 16 = y^2 + 8z - 48

anonymous · Answer

$$y=\sqrt{z ^{2}+6z-40}$$

danjs · Answer

move the 8z and the -48 to the other side...

z^2 - 16z + 64 = y^2

danjs · Answer

take the root of both sides, and you get two answers for y, the + and the - root of all that on the left

danjs · Answer

$$y = \pm \sqrt{z^2-16z+64}$$

danjs · Answer

looking closer, the stuff under the root is a perfect square,   factors to (z-8)^2

so you get  simplified

y = z - 8  or y = -(z-8)

anonymous · Answer

so thats the answer?
because i said y=z-8

anonymous · Answer

@DanJS

danjs · Answer

sorry, back

danjs · Answer

yeah if that is the only choice in the multiple choice , there is also the negative of that , and there is a restriction on the values of z,  but not sur eif you need that