Answer:
The solutions are (0, 4) and (-3, -5).
Explanation:
Yes, first substitute y = 3x + 4 in the first equation:
3x + 4 = -x^2 + 4
x^2 + 3x = 0
x(x + 3) = 0
x = 0, -3
When x = 0 , y = -(0)^2 + 4 = 4 and
when x = -3 , y = -(-3)^2 + 4 = -9 + 4 = -5.