Answer:
y = - 2 or y = 6
Step-by-step explanation:
Given the 2 equations
y = 2x → (1)
y = x² - 3 → (2)
Substitute y = x² - 3 into (1)
x² - 3 = 2x ( subtract 2x from both sides )
x² - 2x - 3 = 0 ← in standard form
(x - 3)(x + 1) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 3 = 0 ⇒ x = 3
x + 1 = 0 ⇒ x = - 1
Substitute these values into (1) for corresponding values of y
x = 3 : y = 2 × 3 = 6
x = - 1 : y = 2 × - 1 = - 2