Question

e
(c) x2 + y2 + 4z2 + 2xy -- 4yz -- 4xz by (x + y - 2z)
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Answer 1

Answer:

begin mathsize 16px style fraction numerator straight x squared plus straight y squared plus 4 straight z squared plus 2 xy minus 4 yz minus 4 xz over denominator straight x plus straight y minus 2 straight z end fraction end style

begin mathsize 16px style equals fraction numerator open parentheses straight x plus straight y minus 2 straight z close parentheses squared over denominator straight x plus straight y minus 2 straight z end fraction space space space space space space space space space space space because open parentheses straight x plus straight y minus straight z close parentheses squared equals straight x squared plus straight y squared plus straight z squared plus 2 xy minus 2 yz minus 2 zx end style

= x + y - 2z