Question

-7x²+9xy -9y² from 11x²+15xy-2y²​

Answer 1

Hope this helps you

Answer 2

Answer:

$(11 {x}^{2} + 15xy - 2 {y}^{2}) - ( - 7 {x }^{2} + \\ 9xy - 9 {y}^{2} ) \\ = 11 {x}^{2} + 15xy - 2 {y}^{2} + 7 {x}^{2} - \\ 9xy + 9 {y}^{2} \\ = 18 {x}^{2} + 6xy + 7 {y}^{2} ans$