Question

factorise 64(2a-b)²-81b²
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Answer 1

Answer:

25(2a−b)

2

−81b

2

=(10a−5b)

2

−(9b)

2

Using [a

2

−b

2

=(a+b)(a−b)], we get

=(10a−5b+9b)(10a−5b−9b)

=(10a+4b)(10a−14b)

=4(5a+2b)(5a−7b)