Answer:
number of adult shirts sold (a) = 20
number of youth shirts sold (b) = 10
Explanation:
a = number of adult shirts sold
y = number of youth shirts sold
30 = a + y
$324.50 = 11.50a + 9.45y
This is the resulting system of equations from the given information in the problem.
Solve for y in the first equation and then substitute the equation for y into the second equation :
a+y=30 --> y=30-a
324.50 = 11.50a + 9.45(30-a)
Solve for a.
324.50 = 11.50a + 283.5 - 9.45a
41 = 2.05a
a = 20
Now that we have solved for a, we can back substitute into our equation for y and solve.
y=30-(20)
y = 10
CHECK:
(20)+(10) = 30 True
(11.50)(20) + (9.45)(10) = 324.5 True