Question

(5x^2-6xy+y^2)+(-8x^2-5xy-y^2)+(x^2+xy-7y^2)

Answer 1

so far i hve -3x-xy^2-7y^4

Answer 2

-2x^2 -10xy -7y^2

Answer 3

im adding the exponents ?

Answer 4

first we expand bracket, collect like terms.
That is (5x^2 - 8x^2 + x^2 - 5xy + xy - 6xy + y^2 - y^2 - 7y^2)=
(-2x^2 - 10xy - 7y^2)