Evaluate the following.

$\frac{(12.5)^3+(7.5)^3}{(12.5)^2+(7.5)^2-12.5×7.5}$

20

a³ + b³ = ( a + b ) ( a² + b² - ab )

( a + b ) = \(\frac{a^3 + b^3}{a^2 + b^2 - ab }\)

$\frac{(12.5)^3+(7.5)^3}{(12.5)^2+(7.5)^2-12.5×7.5}$

By comparing the values of given equation to the formula given above we get to know,

a = 12.5

b = 7.5

So the value of a + b = 12.5 + 7.5 = 20