Question

24. Subtract the sum of 7x ^ 2 - 4y ^ 2 and 4x ^ 2 + 3xy - 4y ^ 2 from the sum of 5x ^ 2 - 3xy - y ^ 2 and x ^ 2 + 2xy - 2y ^ 2 .​

Answer 1

ANSWER:

Sum 1:

7x²- 4y²+ 4x²+ 3xy- 4y²

= 7x²+4x²-4y²-4y²+3xy

=11x²-8y²+3xy

Sum 2:

5x²- 3xy- y²+ x²+ 2xy- 2y²

=5x²+x²-3xy+2xy-y²-2y²

=6x²-xy-3y²

Difference:

(6x²-xy-3y²)-(11x²-8y²+3xy)

6x²-xy-3y²-11x²+8y²-3xy

=6x²-11x²-xy-3xy-3y²+8y²

=-5x²-4xy+5y²

Answer: -5x²-4xy+5y²

Answer 2

24. Subtract the sum of 7x ^ 2 - 4y ^ 2 and 4x ^ 2 + 3xy - 4y ^ 2 from the sum of 5x ^ 2 - 3xy - y ^ 2 and x ^ 2 + 2xy - 2y ^ 2 .