Question

The sum of two numbers is 15. One number is twice as large as the second number. What are the two numbers? Which let statement would you use?

Answer 1

`y=5`
`x=10`

Explanation:

Let `x` be a number and let `y` be the other number:
`x+y= 15`
`x=2y`

Substitute `2y` for `x`:
`2y+y=15`
`3y=15`

`y=5`
`x=10`