Answer:
a) = 7x² + 4y²
b) = 3x + 7xy - 7
Step-by-step explanation:
a) = (9 - 2) x² + (-3 + 7) y²
= 7x² + 4y²
b) = (8 - 5) x + (3 + 4) xy - 7
= 3x + 7xy - 7
