Don L. answered 11/12/15
Tutor
5
(18)
Fifteen years teaching and tutoring basic math skills and algebra
Hi Bianca, set up two equation in x and y and then solve for either the x or y.
Equation 1:
x + y = 9, this represents the number of people and / or it represents the number of each type of ticket.
Equation 2:
x * 240 + y * 910 = 6180, this represents the money spent of each type of ticket.
Solve:
x + y = 9
240x + 910y = 6180
multiply the first equation by -240 and then subtract the two equations to eliminate the x variable.
-240x - 240y = -2160
240x + 910y = 6180
--------------------------------
0x + 670y = 4020
Divide both sides by 670 giving:
y = 6, or 6 first class tickets were purchased.
Substitute for y in equation 1 to find the value for x.
x + 6 = 9
Subtract 6 from both sides gives:
x = 3
Solution: Sarah purchased 3 coach tickets and 6 first class tickets.
Check:
substitute for x and y in the second equation.
3 * 240 + 6 * 910 = 6180
720 + 5460 = 6180
6180 = 6180, values check.
Questions?