1 answer
(click or scroll down)
The way you typed it ....
1.
multiply every term by 2 ...
3z + 12z = 3
15z = 3
z = 3/15 = 1/5
2. each term by x
2 + 2x = x^2 + 2 + 4x
x^2 + 2x = 0
x(x+2) = 0
x = 0 or x = -2
I have a feeling you meant to have brackets in those equations.