For this case we must simplify the following expression:
[tex]x ^ 2-3xy-5xy-7y ^ 2 + 4x ^ 2 + 8y ^ 2[/tex]
We must add similar terms taking into account that:
[tex](x ^ 2 + 4x ^ 2) + (- 3xy-5xy) + (- 7y ^ 2 + 8y ^ 2) =\\5x ^ 2-8xy + y ^ 2[/tex]
Thus, the simplified expression is:
[tex]5x ^ 2-8xy + y ^ 2[/tex]
Answer:
[tex]5x ^ 2-8xy + y ^ 2[/tex]