1. EXAMPLE 3
Standardized Test Practice
SOLUTION
Write verbal models for this situation.

2. EXAMPLE 3
Standardized Test Practice
Equation 1
Equation 2

3. Standardized Test Practice
EXAMPLE 3
Standardized Test Practice
STEP 2
Write a system of equations.
Equation 1
5x + 7y = 2500
Total cost for all T-shirts
Equation 2
8x + 12y = 4200
Total revenue from all T-shirts sold
STEP 3
Solve the system using the elimination method.
Multiply Equation 1 by –8 and Equation 2 by 5 so that the coefficients of x differ only in sign.
5x + 7y = 2500
– 40x – 56y = – 20,000
40x + 60y = 21,000
8x + 12y = 4200
Add the revised equations and solve for y.
4y = 1000
y = 250

4. Standardized Test Practice
EXAMPLE 3
Standardized Test Practice
Substitute the value of y into one of the original equations and solve for x.
5x + 7y = 2500
Write Equation 1.
5x + 7(250) = 2500
Substitute 250 for y.
5x = 2500
Simplify.
x = 150
Solve for x.
The school sold 150 short sleeve T-shirts and 250 long sleeve T-shirts.
ANSWER
The correct answer is C.

5. GUIDED PRACTICE
for Example 3 4.
WHAT IF? In Example 3, suppose the school spends a total of $3715 on T-shirts and sells all of them for $6160. How many of each type of T-shirt are sold?
The school sold 365 short sleeve T-shirts and 270 long sleeve T-shirts.
ANSWER