(x-y)(\(^{x^4}\)+\(x^3.y+x^2y^2+xy^3+y^4\))=\(x^5-y^5\)
b,\(\left(x+y\right)\left(x^4-x^3y+x^2y^2-xy^3+y^4\right)=x^5+y^5\)
c,\(\left(a+b\right)\left(a^3-a^2b+ab^2-b^3\right)=a^4-b^4\)
d,\(\left(a+b\right)\left(a^2-ab+b^2\right)=a^3+b^3\)
chững minh câc hằng thức sau :