Practicing Success
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CUET
General Test
Quantitative Reasoning
Algebra
If a - b = 18 and $a^3 - b^3 = 324$, then find ab.
-102
103
105
-104
If a - b = 18
$a^3 - b^3 = 324$,
then find ab = ?
(a - b)3 = a3 - b3 - 3ab(a-b)
(18)3 = 324 - 3ab(18)
5832 - 324 = -54ab
5508 = -54ab
ab = -102