You changed the mixed numeral into a fraction correctly. Now you need to multiply the fractions. Multiply the numerators together, and multiply the denominators together.
[tex] = \dfrac{23 \times 5}{5 \times 12} [/tex]
Now we could multiply out the numerator and denominator, and then we'd need to reduce the fraction, but before we multiply, we see there is a factor of 5 both in the numerator and in the denominator, so we can reduce before we multiply.