express y in terms of x

Question

mathmale · Answer

Hello again!  I'd suggest that you begin by squaring both sides of this equation.  Then, ask yourself how you'd go about solving the resulting equation for y.  That would be your formula for y in terms of x.

anonymous · Answer

Hi there, thank for replying to this :) so when the squareroot is squared does it just become x+y/y?

anonymous · Answer

@mathmale  :)

mathmale · Answer

Remember, your original equation has a '4' on the left.
Square that as well as square the radical expression on the right.

What's the resulting equation?

anonymous · Answer

im not sure if im right @mathmale

mathmale · Answer

That's just fine!  Your next step is to solve this equation for y.  Hint:  cross-multiply:$$\frac{ 16 }{ 1 }=\frac{ x+y }{ y }$$

anonymous · Answer

or is that the wrong step?

mathmale · Answer

Decide whether you want y on the left or on the right; traditionally, we isolate y on the left.

If 16y = x + y, subtracting y from both sides results in what?

mathmale · Answer

Hint:  16a-a means 16a - 1a = (16-1)a = ??