Answer
Find out the number of refills keith bought and write equation for it .
To prove
Let us assume that the number of refills be x .
a restaurant sells a coffee refill mug for $6.75.
Each refill costs $1.25
Last month keith spent $31.75 on a mug and refills .
Than the equation becomes
6.75 + 1.25 × x = 31.75
6.75 + 1.25x = 31.75
1.25x = 31.75 - 6.75
1.25x = 25
[tex]x = \frac{25}{1.25}[/tex]
x = 20
Therefore the number of refills keith bought be 20 .
