Answer:
Step-by-step explanation:
The ys have to have the same value. That allows you to equate the right side of each y to each other.
-x^2 + 4 = 2x + 1 Subtract the right side from the left side.
-x^2 + 4 - 2x - 1 = 2x-2x +1 - 1 Combine
-x^2 - 2x + 3 = 0 Multiply both sides by - 1
-1(-x^2 - 2x + 3) = 0*-1 Remove the brackets
x^2 + 2x - 3 Factor
(x - 1)(x + 3 )
x - 1 = 0
x = 1
x + 3 = 0
x = - 3
So the line goes through x = 1 or x = - 3
x = 1
y = 2x + 1
y = 2(1) + 1
y = 3
x = - 3
y = 2(-3) + 1
y = - 6 + 1
y = - 5
Does the graph confirm this? See below.
red: y = -x^2 + 4
green: y = 2x + 1
Yes the graph is in agreement.
