What is the simplified form of the quantity 4 z squared minus 16z plus 15 over the quantity 2 z squared minus 11 z plus 15?

Factor the numerator and denominator to get

(2z-3) (2z-5) / (z-3) (2z-5)

Since there is a common factor of (2z - 5) on the numerator and denominator this factor will cancel leaving (2z-3) / (z-3)