Question

In a number between 9 and 100 the product of digit is 20 ans their sum is 9

Answer 1

The numbers are 45 and 54.

Explanation:

t + u = 9

tu = 20

t(9 - t) = 20

9t - t² = 20

t² - 9t + 20 = 0

(t - 4)(t - 5) = 0

t = 4--->u = 5

t = 5--->u = 4

So we have the numbers 45 and 54.