Answer:
equation: x(1.25) + 6.75 = 31.75 refills: 20
Step-by-step explanation:
The mug costs $6.75, and you aren't buying multiple cups, so that number stays the same. The number of refills is "x" since we do not know the amount. Next to "x" we multiply 1.25 for the cost of each refill. So now we have "x(1.25)" then we add $6.75 to the equation, for the mug price. Along with the total at the end. To which we now have "x(1.25) + 6.75 = 31.75"
Now we solve the equation. First, subtract 6.75 from each side
x(1.25) + 6.25 = 31.75
-6.25 -6.25
Now we have "x(1.25) = 25" So we have to divide each side by 1.25
x(1.25/1.25) = 25/1.25
x = 20
Therefore, Kim bought 20 refills. To check our work we can replace x with 20 in the original equation.
20(1.25) + 6.75 = 31.75
25 + 6.75 = 31.75
31.75 = 31.75
I'm not the best at explanations, but I hope this helped! :)