(2x-2y-2z)^2
solve above!I mean expand using sonme sort of formula
plz dont joke me 4 such a questone I am a student of low level I mean low class oh junior class
$\displaystyle (a + b + c)^2 = (a + b + c)(a + b + c) =$ $\displaystyle a.a + a.b + a.c + b.a + b.b + b.c + c.a + c.b + c.c = a^2 + b^2 + c^2 + 2ab + 2ac + 2bc$
So, take $\displaystyle a=2x$, $\displaystyle b=-2y$, $\displaystyle c=-2z$,
$\displaystyle 4x^2 + 4y^2 + 4z^2 - 8xy - 8xz + 8yz$
Or you could do this without using a formula,
$\displaystyle (2x - 2y - 2z)^2 = (2x - 2y - 2z)(2x - 2y - 2z) = $$\displaystyle 4x^2 - 4xy - 4xz -4xy + 4y^2 + 4yz - 4xz + 4yz + 4z^2 = 4x^2 + 4y^2 + 4z^2 - 8xy - 8xz + 8yz$
or you could use the multinomial theorem
(topsquark's method is perhaps easier, but you'll get a messy expression anyway)