
Answer:
1,084 tickets were sold that cost $10
1,291 tickets were sold that cost $20
767 tickets were sold that cost $30
Step-by-step explanation:
Let
x ----> the number of tickets that cost $10 sold
y ----> the number of tickets that cost $20 sold
z ----> the number of tickets that cost $30 sold
we know that
x+y+z=3,142 -----> equation A
10x+20y+30z=59,670 ----> equation B
y=x+207 ----> equation C
substitute equation C in equation A and equation B
x+(x+207)+z=3,142 ----> 2x+z=2,935 ----> equation D
10x+20(x+207)+30z=59,670 ---> 30x+30z=55,530 ----> equation E
Solve the system of equations D and E by graphing
The solution is the intersection point both graphs
The solution is the point (1,084,767)
so
x=1,084, z=767
see the attached figure
Find the value of y
y=x+207 ----> y=1,084+207=1,291
therefore
1,084 tickets were sold that cost $10
1,291 tickets were sold that cost $20
767 tickets were sold that cost $30