Q6 of 9 Page 151

Expand (– 2x + 5y – 3z)2.

Using formula:


(a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca)


Expanding the given equation


(– 2x + 5y – 3z)2 = 4x2 + 25y2 + 9z2 + 2(– 10xy – 15yz + 6xz)


(– 2x + 5y – 3z)2 = 4x2 + 25y2 + 9z2 – 20xy – 30yz + 12xz


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