First we can move c^-3 to the denominator as c^3 since it has a negative exponent.
(5a^2*b^2)/(2a^3*c^3)
Now we can reduce the expression. We have 'a' terms on top and bottom, so to reduce we just subtract the exponents. We have a^2 on top and a^3 on bottom, so we are left with a^1 on bottom.
(5b^2)/(2a*c^3)