Question

Answer 1

\(a,=2xy\left(y-5\right)\\ b,=x\left(x+y\right)-5\left(x+y\right)\\ =\left(x-5\right)\left(x+y\right)\\ c,=25-\left(x^2-2xy+y^2\right)\\ =25-\left(x-y\right)^2\\ =\left(5-x+y\right)\left(5+x-y\right)\)

Answer 2

a) \(2xy^2-10xy\)

\(=2xy\left(y-5\right)\)

b) \(x^2+xy-5x-5y\)

\(=x\left(x+y\right)-5\left(x+y\right)\)

\(=\left(x-5\right)\left(x+y\right)\)

c) \(25-x^2-y^2+2xy\)

= \(25-\left(x^2+y^2-2xy\right)\)

= \(25-\left(x-y\right)^2\)

= \(\left(5-x+y\right)\left(5+x-y\right)\)