\(\left(x+2y\right)^5\\ =\left(x+2y\right)^2\left(x+2y\right)^3\\ =\left(x^2+4xy+4y^2\right)\left(x^3+6x^2y+12xy^2+8y^3\right)\\ =x^5+6x^4y+12x^3y^2+8x^2y^3+4x^4y+24x^3y^2+48x^2y^3+32xy^4+4x^3y^2+24x^2y^3+48xy^4+32y^5\\ =x^5+10x^4y+40x^3y^2+80x^2y^3+10x^4y+80xy^4+32y^5\)