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Question
Expand the following, using suitable identity:
`[1/4a-1/2b+1]^2`
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Solution
It is known that,
(x + y + z)2 = x2 + y2 + z2 + 2xy + 2yz + 2zx
`[1/4a - 1/2b + 1]^2`
= `(1/4a)^2 + (-1/2b)^2 + (1)^2 + 2(1/4a)(-1/2b) + 2(-1/2b)(1) + 2(1)(1/4a)`
= `1/16a^2 + 1/4b^2 + 1 - 1/4ab - b + 1/2a`
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