Question

Please help!!!

Answer 1

The sum of x^2−3xy−y^2 and 2x^2+5xy−4y^2:

x^2−3xy−y^2 + 2x^2+5xy−4y^2

= 3x^2 + 2xy - 5y^2

From 6x^2−7xy+8y^2 subtract the sum of x^2−3xy−y^2 and 2x^2+5xy−4y^2:

6x^2−7xy+8y^2 - (3x^2 + 2xy - 5y^2)

= 6x^2−7xy+8y^2 - 3x^2 - 2xy + 5y^2

= 3x^2−9xy + 13y^2

Answer

3x^2−9xy + 13y^2