Expand the following, using suitable identities: (−2x+5y−3z)2.
(−2x+5y−3z)2
Here a = -2x, b = 5y and c = -3z
= (−2x)2 + (5y)2 + (−3z)2+ 2(-2x)(5y) + 2(5y)(-3z) + 2(-3z)(-2x) (Expanding using (a+b+c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca )
= 4x2 + 25y2+ 9z2 - 20xy -30yz + 12zx