Answer:
-4x^2 – 2xy + 2y^2 + 9
Explanation:
First, perform the indicated multiplications: Multiply each 7x^2, -3xy and -3^2 by -1:
If this is done properly, we get: -7x^2 + 3xy + 9
Now rewrite (3x^2 – 5xy + 2y^2)-(7x^2 – 3xy - 3^2) as
3x^2 – 5xy + 2y^2 - 7x^2 + 3xy + 9)
Combining the x^2 terms, we get:
-4x^2 – 5xy + 2y^2 + 3xy + 9.
Combining the xy terms, we get:
-4x^2 – 2xy + 2y^2 + 9
This is the final answer (sum), since none of these four terms can be combined.