we start off by multiplying 2x/5b by the reciprocal of 4x^3/15bx, which is 15bx/4x^3
2x/5b • 15bx/4x^3
so now we cross simplify and we are left with:
3x/2x^2
and we can simplify that fraction into
3/2x.
that's as simplified as it can get (:
hope that helped!! xx