example (x+y)³
solve:(x)³+3(x)²(y)+3(x)(y)²+(y)³
then u multiply the x in cube =x³ then,first the x² the multiply the 3xX²xy =3x(squared)y then the third is multiply the 3xXxy²=3xy² the last is multiply the y in cube is =y³
te answer is=x³+3x²y+3xy²+y³
