सरल कीजिए (4.2)3 - (1.2)3 /(4.2)2 + 5.04 + (1.2)2 - SSC STUDY

सरल कीजिए $\dfrac{(4.2)^3 - (1.2)^3}{(4.2)^2 + 5.04 + (1.2)^2}$

Options
a) 2
b) 3
c) 5
d) 1

Solution

माना a = 4.2
b = 1.2
ab = 5.04
Formula :
a³ – b³ = (a-b) (a² +ab + b²)
$\frac{(a-b)(a^2+ab+b^2)}{a^2+ab+b^2}$ = (a-b)
(a-b) = (4.2 – 1.2) = 3

Ans: 3