Question

What is 3x+4y=16 for x

Answer 1

3x + 4y = 16           Write original equation     
3x + 4y - 4y = -4y + 16          Subtract 4y from each side
3x = -4y +16                    Simplify
3x/3 = -4y/3 + 16/3      Divide each side by three
x = -4y/3 +16/3             Simplify

I hope this helps!