It's not very clear, but I'm assuming that problem looks like the following:

     (24·x⁵·y⁸)/(30·x³·y¹⁰)

First, notice that 6 is a factor of both the coefficients in the numerator and the denominator. So the expression can be reduced as follows:

     (6·4·x⁵·y⁸)/(6·5·x³·y¹⁰) = (4·x⁵·y⁸)/(5·x³·y¹⁰)

When dividing exponents with like bases, we keep the same base and subtract the smaller exponent from the larger exponent. For instance, 

     x⁵/x³ = x^5-3/x^3-3 = x²/x⁰ = x²/1 = x²

     y⁸/y¹⁰ = y^8-8/y^10-8 = y⁰/y² = 1/y²

Therefore,

     (4·x⁵·y⁸)/(5·x³·y¹⁰) = (4·x^5-3·y^8-8)/(5·x^3-3·y^10-8)

                             = (4·x²·y⁰)/(5·x⁰·y²)

                             = (4·x²·1)/(5·1·y²)

                             = (4·x²)/(5·y²)

Thus,

     (24x⁵y⁸)/(30x³y¹⁰) = (4x²)/(5y²)