Rút gọn các biểu thức sau đây

a)(2x-y)(4x2-2xy+y2)
b)(3x-4)(x+4)+(5-x)(2x2+3x-1)
c)A=x(3x+12)-(7x-20)+x2(2x+3)-x(2x2+5)
d)B=3(2x-1)-5(x-3)+6(3x-4)-19x
e)3x+2(5-x)=0
f)3x2-3x(x-2)=36
g)14x2y-21xy2+28x2y2
h)x(x+y)-5x-5y
i)10x(x-y)-8(y-x)
k)(3x+1)2-(x+1)2
l)x3+y3+z3-3xyz
m)5x2-10xy+5y2-20z2
n)x3-x+3x2y+3xy2+y3-y
p) x3-2x2+x-xy2
J)x2+7x-8