Question

The sum of the two digits of a number is 9. If the tens digit is one-half the units digit, what is the number?

Let t = the tens digit, u = the units digit, and t+u = 9. Which of the following equations would complete the system?
t-u=1/2

t=1/2u

u=1/2t

Answer 1

t=1/2u

Explanation:

Since t=tens digit and u=units digit, as given in the equation that means that t+u=9. Since the tens digit is one-half the units digit that means:
`t=(1)/(2)u` since it's one half the units digit.