9514 1404 393
Answer:
(x, y) = (-3, -5) and (1, 3)
Step-by-step explanation:
Equate the expressions for y.
-x^2 +4 = 2x +1
4 = x^2 +2x +1 . . . . . add x^2
4 = (x +1)^2 . . . . . . . . rewrite as square
±2 = x +1 . . . . . . . . . . take square root
x = -1 ±2 = {-3, 1} . . . . subtract 1
y = 2x +1 = 2{-3, 1} +1 = {-6, 2} +1 = {-5, 3} . . . . find corresponding y-values
The solutions are ...
(x, y) = (-3, -5) and (1, 3)