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

Please do not copy-paste my work.

so this is the problem they want you to write an equation for + solve

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?

let's go through the steps
step 1: "Choose a variable to represent one of the unknowns."
the problem is talking about some unknown number, made of two digits (the tens and the ones). I'll let t = the tens digit. I will also let o = the ones digit.

Answer 2

step 2: 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.

"The tens digit of a number is twice the ones digit." ---> t = 2o

"The sum of the digits in the number is 12." ---> t + o = 12

therefore, since the problem says to re-write an equation in terms of one variable only, we can plug in t = 2o into the second equation and re-write the equation in terms of o only.

Answer 3

for the last part, simply solve the equation from step 2

once you have o, you can plug this back into t = 2o to get t