Question

Answer 1

`a)1/2x^3y(3x-y)`

`=1/2x^3y*3x+1/2x^3y*(-y)`

`=3/2x^(3+1)y-1/2x^3y^(1+1)`

`=3/2x^4y-1/2x^3y^2`

`b)5xy(2x-7xy)`

`=5xy*2x-5xy*7xy`

`=(5*2)*x^(1+1)y+(-5*7)x^(1+1)y^(1+1)`

`=10x^2y-35x^2y^2`

`c)-4xy(5xy-3x-2)`

`=-4xy*5xy-4xy*(-3x)-4xy*(-2)`

`=(-4*5)x^(1+1)y^(1+1)+(-4*-3)x^(1+1)y+(-4*-2)xy`

`=-20x^2y^2+12x^2y+8xy`

`d)5x^2y(2x^2-3x+1)`

`=5x^2y*2x^2+5x^2y*(-3x)+5x^2y*1`

`=(5*2)x^(2+2)y+(5*-3)x^(2+1)y+5x^2y`

`=10x^4y-15x^3y+5x^2y`