(x^2-5xy)(-3xy) (2x^3-3x^2+x+30):(x+2) (x+3)^2+(7-x)^2+2(x+3)(7-x) giùm mình đi nha các bạn

`(x^2-5xy)(-3xy)`

`=x^2.(-3xy)-5xy.(-3xy)`

`=-3x^3 y+15x^2 y^2`

`(2x^3-3x^2+x+30):(x+2)`

`=(2x^3+4x^2-7x^2-14x+15x+30):(x+2)`

`=[2x^2(x+2)-7x(x+2)+15(x+2)]:(x+2)`

`=(x+2)(2x^2-7x+15):(x+2)`

`=2x^2-7x+15`

`(x+3)^2+(7-x)^2+2(x+3)(7-x)`

`=(x+3+7-x)^2`

`=10^2`

`=100`