Question
Find the value of using the short-cut method:
$(84)^3$
$(84)^3$
✓
Answer
$(84)^3$ We know that short-cut method for finding the cube of any two digit numbers is as given.
$(a+b)^3=a^3+3 a^2 b+3 a b^2+b^3$
$=a^2 \times a+a^2 \times 3 b+b^2 \times 3 a+b^2 \times b$
Here,
$a=8$
$b=4$
$(a+b)^3=a^3+3 a^2 b+3 a b^2+b^3$
$=a^2 \times a+a^2 \times 3 b+b^2 \times 3 a+b^2 \times b$
Here,
$a=8$
$b=4$
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