solve 3x + x(x-1)=0 and find the y intercepts of f(x)=3x + x (x-1)

3x + x(x-1)=0

3x + x^2 - x = 0
x^2 + 2x = 0
x (x - 2) = 0
x=0 x=2
There are two answers, x=0 and x=2

To find the y intercepts, set x = 0:
y = 3x + x(x-1)
y = 3(0) + 0(0-1)
y = 0 + 0
y = 0
So the y intercept is at 0