\begin{tabular}{l} 4. 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. Write an equation you can use to find \\ the number of refills that Keith bought. \\ Variable: \\ Coefficient: \\ Constants: \\ \hline Equation: \end{tabular}

To find the number of refills Keith bought, we can set up an equation based on his total spending. The cost of the mug is a constant \( \$6.75 \), while each refill costs \( \$1.25 \). If we let \( r \) represent the number of refills, the total amount spent can be expressed as: \[ 6.75 + 1.25r = 31.75 \] In this equation, the variable is \( r \) (the number of refills), the coefficient is \( 1.25 \) (the cost per refill), and the constants are \( 6.75 \) (the initial cost of the mug) and \( 31.75 \) (the total amount spent). Now, if you find it tricky to balance your coffee budget, remember to factor in your refill costs before diving in! Keeping track of these elements can help you steer clear of overspending and ensure maximum coffee enjoyment without breaking the bank!