Rút gọn:
a) \(\left(x-2y\right)\left(3xy+5y^2+x^2\right)\)
b) \(\left(2x+3\right)\left(4x^2-6x+9\right)-2\left(4x^3-1\right)\)
c) \(\left(x-3y\right)^2-2\left(x-3y\right)\left(3y+x\right)+\left(x+3y\right)^2\)
d) \(\left(x^2-x+1\right)\left(x-1\right)-3x\left(x+1\right)^2\)
nhân ra hết là đc
kệ chẳng quan tâm