a: \(=5y^2\left(5x+3\right)\)
b: \(=6x\left(x-y\right)+3y\left(x-y\right)\)
\(=3\left(x-y\right)\left(2x+y\right)\)
\(a,25xy^2+15y^2=5y^2\left(5x+3\right)\\ b,6x\left(x-y\right)+3xy-3y^2=6x\left(x-y\right)+3y\left(x-y\right)=\left(6x+3y\right)\left(x-y\right)=3\left(2x+y\right)\left(x-y\right)\)
a)25xy2+15y2=5y2(5x+3)
b)6x(x-y)+3xy-3y2=6x(x-y)+(3xy-3y2)=6x(x-y)+3y(x-y)=(x-y)(6x+3y)=3(x-y)(2x+y)
\(\text{a, 25xy^2 + 15y^2}\\ =5y^2\left(5x+3\right)\)
\(\text{b, 6x(x-y) + 3xy - 3y^2 =6x^2-6xy+3xy-3y^2}\\ =3\left(x^2-2xy+xy\right)-y^2\\ =3\left(x-xy\right)^2-y^2\\ =3\left(x-xy-y\right)\left(x-xy+y\right)\)