Expand $\left(\frac{x}{3}+\frac{y}{5}\right)^3$
Answer & explanation
Correct answer: option 4
(a + b)3 = a3 + b3 + 3ab(a+b)
$\left(\frac{x}{3}+\frac{y}{5}\right)^3$
So by expanding this cubic equation we get,
$\frac{x^3}{27}+\frac{x^2 y}{15}+\frac{x y^2}{25}+\frac{y^3}{125}$