Kim bought 4 shirts and 3 pairs of jeans for $109.85.
Jim bought 6 shirts and 1 pair of jeans for $94.95.

Each shirt costs the same amount.
Each pair of jeans costs the same amount.

What is the cost, in dollars, for 1 pair of jeans?

Question

Kim bought 4 shirts and 3 pairs of jeans for $109.85.
Jim bought 6 shirts and 1 pair of jeans for $94.95.

Each shirt costs the same amount.  
Each pair of jeans costs the same amount.

What is the cost, in dollars, for 1 pair of jeans?

mathstudent55 · Answer

Write a system of equations, then solve it.
Let number of shirts = s
Let number of jeans = j
Kim: 4s + 3j = 109.85
Jim: 6s + j = 94.95
The system of equations is:

4s + 3j = 109.85
6s + j = 94.95

Do you know how to solve a system of equations?

anonymous · Answer

yes

mathstudent55 · Answer

ok, great

anonymous · Answer

so am I solving for j then?

anonymous · Answer

hello?

anonymous · Answer

yes.....

anonymous · Answer

but how does that give me the cost of the jeans?

anonymous · Answer

the j is representing the cost of 1 pair of jeans not the number.......the number of them are the numbers given that are multiplying the j.......

mathstudent55 · Answer

Solve the second equation for j, which is easy. Then substitute that into the first equation. Then you solve the first equation for s. Once you have s, insert it into either of the two original equations and solve for j.

anonymous · Answer

j=-6s+94.95

mathstudent55 · Answer

4s + 3j = 109.85
6s + j = 94.95   ---->     j = 94.95 - 6s
Now that you have the second equation solved for j, insert what j is into j of the first equation.
Yes you got j correct.

anonymous · Answer

4s+3(-6s+94.95)=109.85

mathstudent55 · Answer

First equation:
4s + 3j = 109.85 now substitute j in this eq with -6s + 94.95

mathstudent55 · Answer

excellent, you're doing it before I even write it

mathstudent55 · Answer

Now multiply out the 3 on the left side

anonymous · Answer

s=12.71
?

mathstudent55 · Answer

4s+3(-6s+94.95)=109.85
4s + 3*(-6s) + 3*94.95) = 109.85
4s - 18s + 284.85 = 109.85
-14s = -175
s = 12.5

anonymous · Answer

s= 12.50

anonymous · Answer

Ya, I put -178 instead of -175

anonymous · Answer

THANKS!!!!

mathstudent55 · Answer

Now replace s = 12.5 into either of the original equations to get j.

mathstudent55 · Answer

Are you sure you copied the problem correctly?

anonymous · Answer

yes

anonymous · Answer

it is $12.50 for the shirts

anonymous · Answer

j would equal $19.95

mathstudent55 · Answer

Right. $12.50 is the price, not the number of shirts. It does make sense.

mathstudent55 · Answer

Correct. Good job @ballerina789

anonymous · Answer

I just needed a boost. Thanks for that.