Answer:
(x, y) = (-3, -5) or (1, 3)
Step-by-step explanation:
You can equate the expressions for y, then solve the resulting quadratic.
-x^2 +4 = 2x +1
4 = x^2 +2x +1 . . . . add x^2
4 = (x +1)^2 . . . . . . . write as a square
±2 = x +1 . . . . . . . . . take the square root
x = -1 ±2 = -3 or +1 . . . subtract 1
So, the solutions have x-values of -3 or +1. The corresponding y-values can be found from ...
y = 2x +1
y = 2(-3) +1 = -5 or y = 2(1) +1 = 3
Solutions are ...
(x, y) = (-3, -5) or (1, 3)
