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Question
Verify the following:
(5x + 8)2 – 160x = (5x – 8)2
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Solution
Taking L.H.S. = (5x + 8)2 – 160x
= (5x)2 + (8)2 + 2 × 5x × 8 – 160x ...[Using the identity, (a + b)2 = a2 + 2ab + b2]
= (5x)2 + (8)2 + 80x – 160x
= (5x)2 + (8)2 – 80x
= (5x)2 + (8)2 – 2 × 5x × 8
= (5x – 8)2 ...[∵ a2 + b2 – 2ab = (a – b)2]
= R.H.S.
Hence verified.
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