Question

Follow the process for establishing a set of equations: Choose a variable to represent one of the unknowns. Express the remaining unknowns in terms of the variable you chose in step 1. Look for a relationship between the unknowns given in the problem. Write an equation. (Look for the other relationship given in the problem.) The tens digit of a number is twice the ones digit. The sum of the digits in the number is 12. What is the number? Include the entire process for establishing a set of equations, the solution, and an explanation of what the solution means in terms of the variables. Complete your work in the space provided.

Answer 1

Number = 84

Explanation:

Given

Represent Tens with T and Ones digit with U

`T = 2U`

`T + U = 12`

Required

Find the number

Substitute 2U for T in the second equation

`2U + U = 12`

`3U = 12`

Divide through by 3

`U = 4`

Substitute 4 for U in the first equation

`T = 2 * 4`

`T = 8`

Hence, the number is 84