Question

Find the value of $\frac{{43}^3+{47}^3}{{43}^2-43\times 47+{47}^2}$ using a suitable identity.

• A. 43
• B. 47
• C. 45
• D. 90

Answer 1

The correct option is D 90

Using the identity $a^3+b^3=(a^2-ab+b^2)(a+b)$
On taking $a=43$ and $b=47$,
the given expression becomes:
$\Rightarrow$ $\frac{a^3+b^3}{a^2-ab+b^2}=a+b$

$\frac{{43}^3+{47}^3}{{43}^2-43\times 47+{47}^2}$

$=43+47$
$=90$.