Expand as a binomial series and simplify
(2x + y^3)^5
use pascals triangle
1 5 10 10 5 1
for example
Expand (2 + 3x)5.
Applying the general rule of ascending and descending indexes and the coefficients from Pascal we can immediately expand the above equation (if we set a to 2 and b to 3):
25 + 5(24)(3x) + 10(23)(3x)2 + 10(22)(3x)3 + 5(2)(3x)4 + (3x)5