InterviewSolution
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InterviewSolution
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Factorise : 49 (2x + 3y)2 – 70 ( 4x2 – 9y2) + 25 (2x – 3y)2(a) 4 (x – 9y)2 (b) 9 (x + 4y)2 (c) 16 (x + 9y)2 (d) 16 (x – 9y)2 |
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Answer» (c) 16 (x + 9y)2 49 (2x + 3y)2 – 70 ( 4x2 – 9y2) + 25 (2x – 3y)2 = (7(2x + 3y))2 - 2 x 7(2x + 3y) x 5(2x - 3y) + (5(2x - 3y))2 = [7(2x + 3y) - 5(2x - 3y)]2 = [14x + 21y - 10x + 15y]2 = (4x + 36y)2 = (4(x + 9y))2 = 16(x + 9y)2 |
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