Instead of doing the problem for you, I will do another one exactly like it, so
you can use it as a model to do yours by. Here is the one that has different
numbers.
A group of adults and kids went to see a movie. Tickets cost $8.50 each for
adults and $4.50 each for kids, and the group paid $66.00 in total. There were 6
fewer adults than kids in the group. How many adults and how many kids were in
the group?
Make this chart:
Cost Cost
Type Number of of
of of EACH ALL
ticket tickets ticket tickets
-------------------------------------------
Adults
Kids
-------------------------------------------
TOTAL
>>There were 6 fewer adults than kids in the group.<<
Since "kids" is mentioned second,
let x = of kids in the group. So we put x for the
number of kids.
Then the number of adults is 6 fewer than that, so we
subtract 6 and get x-6 adults. So we put x-6 for the
number of adults:
Cost Cost
Type Number of of
of of EACH ALL
ticket tickets ticket tickets
-------------------------------------------
Adults x-6
Kids x
-------------------------------------------
TOTAL
Tickets cost $8.50 each for adults and $4.50 each for kids.
So we fill in the cost of each kind of ticket.
Cost Cost
Type Number of of
of of EACH ALL
ticket tickets ticket tickets
-------------------------------------------
Adults x-6 $8.50
Kids x $4.50
-------------------------------------------
TOTAL $66.00
To get the Cost of ALL adult tickets we multiply $8.50
times the number of adult tickets which is $8.50(x-6).
So we fill that in on the right for the cost of all adult
tickets.
To get the Cost of ALL kids tickets we multiply $4.50
times the number of adult tickets which is $4.50x.
So we fill that in on the right for the cost of all kid's
tickets. Then by the word TOTAL, we put $66.00
Cost Cost
Type Number of of
of of EACH ALL
ticket tickets ticket tickets
-------------------------------------------
Adults x-6 $8.50 $8.50(x-6)
Kids x $4.50 $4.50x
-------------------------------------------
TOTAL $66.00
The equation comes from the column on the right




8.50(x-6) + 4.50x = 66.00
Get rid of decimals by multiplying every term by 10:
85(x-6) + 45x = 660
85x - 510 + 45x = 660
130x - 510 = 660
130x = 1170
x = 9 = the number of kid's tickets,
and the number of kids.
The number of adults tickets is x-6 or 9-6 or 3 adult tickets,
and 3 adults.
Checking: 3 Adults is $25.50 and 9 Kids is $40.50
And indeed $25.50 + $40.50 = $66.00
Now use this as a model and do yours. It's exactly the same.
Edwin