Answer
Subtract [tex]7x^2 -5xy+8y^2[/tex] from [tex]-2x^2 -15xy+9y^2[/tex]
then;
[tex]-2x^2 -15xy+9y^2 - (7x^2 -5xy+8y^2)[/tex]
Remove the bracket we have;
[tex]-2x^2 -15xy+9y^2 - 7x^2 + 5xy - 8y^2[/tex]
Like terms are those terms which have same variable to the same power.
Combine like terms;
[tex]-9x^2 -10xy+y^2[/tex]
Therefore, Subtracting [tex]7x^2 -5xy+8y^2[/tex] from [tex]-2x^2 -15xy+9y^2[/tex] we get [tex]-9x^2 -10xy+y^2[/tex]
