Question

1)x(x-y)-y(y-x)
2)2(y^2-5)-5(2-y^2
3)(ab-4)^2
4)(1-b)^2
помогите решить

Answer 1

1)x^2-xy-y^2+xy=x^2y^2
2)2y^2-10-10+5y^2=7y^2-20