Question

10)Subtract the sum of (x 2 + 2y 2 + 7x 2y) and (x 2 − 3xy 2 ) from the sum of (x 2 − y 2 − xy) and (3x 2 − 2y 2 + 7).

Answer 1

Sum = x²+2y²+7x²y + x²-3xy²

= 2x²+2y²+7x²y-3xy²

Sum = x²-y²-xy + 3x²-2y²+7

= 4x²-3y²-xy

Subtraction = (4x²-3y²-xy) - (2x²+2y²+7x²y-3xy²)

= 4x²-3y²-xy-2x²-2y²-7x²y+3xy²

= 2x²-5y²-xy-7x²y+3xy²

Hope it helps!!

Thank you