Let n = number of records.
Each record costs $7, so n records cost 7n.
She then spent $3, so the total spent is 3n + 3.
She spent a total of $24, so 3n + 3 must equal 24. That gives us the following equation.
7n + 3 = 24
Subtract 3 from both sides.
7n = 21
Divide both sides by 7.
n = 3
Answer: She bought 3 records.
