Answer:
x = -2, y = 9
Explanation:
x + y = 7 --1
2x² + y² = 35 - 3xy --2
For 1, make y the subject.
y = 7 - x
Substitute y = 7 - x into 2.
2x² + (7 - x)² = 35 - 3x(7 - x)
Simplify and solve for x.
2x² + (49 - 14x + x²) = 35 - 21x + 3x²
3x² - 14x + 49 = 3x² - 21x + 35
7x = -14
x = -2
Substitute x = -2 into y = 7 - x.
y = 7 - (-2)
= 9
Thus, x = -2, y = 9