Question

)Find the sum of x²+
xy - y² , -x² - xy+2 y² and x²-xy-
y²

Answer 1

Answer:

Let λ will be added

∴x

2

+xy+y

2

+λ=2x

2

+3xy

⇒λ=x

2

+2xy−y

2

Answer 2

Answer:

$x {}^{2} + xy - y {}^{2} + ( - x {}^{2} - xy + 2y {}^{2} ) + (x {}^{2} - xy - y {}^{2} ) \\ = x {}^{2} - xy$