Did I do these probelms correctly?

Find the intercepts

1. y^2 = x^2 - 4x
y^2 = x(x - 4)
Y intercepts
y^2 = 0(0 - 4)
(0,0)
x intercepts
0 = x(x - 4)
0 = x - 4
4 = x
(4,0)

2. y = (x (x + 3))/(3x + 1)^2
y intercetps
y = (0(0 + 3))/(3(0) +1)^2
y = 3/1
(0,3)
x intercepts
0 = (x (x + 3))/(3x + 1)^2
0 = x(x + 3)
-3 = x
(-3,0)

correct, except in your last part ...

0 = x(x + 3)
so x = 0 or x = -3
so you have 2 x intercepts, (0,0) and (-3,0)
you only had one of those.