Answer:
(1, - 1) , (3, 3 )
Explanation:
Given the 2 equations
3 + y - 2x = 0 → (1)
3x² + 2y² - 4xy = 9 → (2)
In (1) subtract 3 - 2x from both sides
y = 2x - 3 → (3)
Substitute y = 2x - 3 into (2)
3x² + 2(2x - 3)² - 4x(2x - 3) = 9 ← distribute and simplify left side
3x² + 2(4x² - 12x + 9) - 8x² + 12x = 9
3x² + 8x² - 24x + 18 - 8x² + 12x = 0
3x² - 12x + 18 = 9 ( subtract 9 from both sides )
3x² - 12x + 9 = 0 ( divide through by 3 )
x² - 4x + 3 = 0 ← in standard form
(x - 1)(x - 3) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 1 = 0 ⇒ x = 1
x - 3 = 0 ⇒ x = 3
Substitute these values into (3) for corresponding values of y
x = 1 : y = 2(1) - 3 = 2 - 3 = - 1 ⇒ (1, - 1 )
x = 3 : y = 2(3) - 3 = 6 - 3 = 3 ⇒ (3, 3 )