`Vd2`

`a,(6x−5y^2).(3x^2−2y)`

`=6x.(3x^2−2y)−5y^2.(3x^2−2y)`

`=6x.3x^2 -6x . 2y-5y^2  .3x^2 + 5y^2.2y`

`=18x^3−12xy−15x^2 y^2+10y^3`

`b,(15x−6y).(4xy+5xy)`

`=(15x−6y).9xy`

`=15x . 9xy-6y . 9xy`

`=135x^2 y−54xy^2`

`c,(10xy+8x^2 y).(2xy^2−4xy)`

`=10xy.(2xy^2−4xy)+8x^2 y.(2xy^2−4xy)`

`=10xy . 2xy^2 - 10xy . 4xy +8x^2 y. 2xy^2 - 8x^2 y .4xy`

`=20x^2 y^3−40x^2 y^2+16x^3 y^3−32x^3 y^2`

`d,(3xy^2 + 4 x^2 y).(5x+6y)`

`=3xy^2.(5x+6y)+4x^2 y.(5x+6y)`

`=3xy^2 .5x + 3xy^2.6y + 4x^2 y . 5x +4x^ y .6x`

`=15x^2 y^2+18xy^3+20x^3 y+24x^2 y^2`

`=(15x^2 y^2+24x^2 y^2)+18xy^3+20x^3 y`

`=39x^2 y^2+18xy^3+20x^3 y`

`---`

`@zil`