SOLUTION: Jen Butler has been pricing Speed-Pass train fares for a group trip to New York. Three adults and four children must pay $122. Two adults and three children must pay $87. Find the

Algebra ->  Graphs -> SOLUTION: Jen Butler has been pricing Speed-Pass train fares for a group trip to New York. Three adults and four children must pay $122. Two adults and three children must pay $87. Find the       Log On


   



Question 283672: Jen Butler has been pricing Speed-Pass train fares for a group trip to New York. Three adults and four children must pay $122. Two adults and three children must pay $87. Find the price of the adult's ticket and the price of a child's ticket.
Answer by JenniferTutors(83) About Me  (Show Source):
You can put this solution on YOUR website!
In this word problem, I pulled out two equations:
Three adults and four children pay 122:
a = adults
c = children
3a + 4c = 122

Two adults and three children pay 87:
2a + 3c = 87
I used the Elimination Method to solve by subtracting the equations:
3a%2B4c=122-2a%2B3c=87

Better form this way, Subtract:
3a + 4c = 122
2a + 3c = 87
a + c = 35
Now you can subtract one of the variables to the other side to get one by itself, either variable is fine:
a+%2B+c+=+35
c+=+35+-+a
Now place the value of c into the first equation:
3a+%2B+4%2835-a%29+=+122
3a+%2B+140+-+4a+=+122
Combine the a's (like terms)
-a+%2B+140+=+122
Subtract the 140 from the left to the right side of the equation:
-a+=+122-140
-a+=+-18
Divide by a negative 1 to get a positive and to both sides:
-a%2F-1+=+-18%2F-1
a+=+18
Now you have the value of tickets for adults. You can place the value of a into the second equation to solve for c.
2%2818%29+%2B+3c+=+87
36+%2B+3c+=+87
Subtract the 36 from the left to right side of the equation:
3c+=+87+-+36
3c+=+51
Divide 3 into itself and the right side:
3c%2F3+=+51%2F3
c+=+17
If you Check: adults = 18, children = 17
Place the values into the first equation:
3%2818%29+%2B+4%2817%29+=+122
54%2B68=122
122=122