Question

Rationalise the denominator of 6-4√2/6+4√2

Answer 1

(6-4√2)/(6+4√2
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(6-4√2)/(6+4√2) × (6-4√2)/(6-4√2)
=(6-4√2)(6-4√2)/(6+4√2)(6-4√2)
=(6-4√2)²/(6²-(4√2)²)
=[6²+(4√2)²-2(6)(4√2)]/(36-16(2))
=(36+16(2)-48√2)/(36-32)
=(36+32-48√2)/4
=(68-48√2)/4
=68/4 - 48√2/4
= 17 - 12√2