Question

alice has $90 to spend on new clothes. she wants to buy some shirts for $20 each. if she has a coupon for $10 off her total purchase, how many shirts can she buy?

Explanation:

Step1: Define total budget after coupon

Let $x$ = number of shirts. Total cost before coupon: $20x$. After $10 off, total cost is $20x - 10$. This must be ≤ $90.
Expression: $20x - 10 \leq 90$

Step2: Isolate the variable term

Add 10 to both sides to cancel the -10.
Expression: $20x \leq 90 + 10$
$20x \leq 100$

Step3: Solve for x

Divide both sides by 20 to find x.
Expression: $x \leq \frac{100}{20}$
$x \leq 5$

Step4: Verify feasibility

Since x must be a non-negative integer, the maximum whole number of shirts is 5.

Answer:

Alice can buy 5 shirts.