Question
Evaluate the using suitable identity: $(998)^3$
✓
Answer
$(998)^3$
$=(1000-2)^3=(1000)^3-(2)^2-3(1000)(2)(1000-2)$
$\left(\text { Using Identity }(a-b)^3=a^3-b^3-3 a b(a-b)\right)$
$=1000000000-8-6000(1000-2)$
$=1000000000-8-6000000+12000$
$=994011992$
$=(1000-2)^3=(1000)^3-(2)^2-3(1000)(2)(1000-2)$
$\left(\text { Using Identity }(a-b)^3=a^3-b^3-3 a b(a-b)\right)$
$=1000000000-8-6000(1000-2)$
$=1000000000-8-6000000+12000$
$=994011992$
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