A pair of pants costs twice as much as a shirt. The total cost of 1 pair of pants and 1 shirt is $18. If s represents the cost of 1 shirt, which equation could you use to find the cost of 1 shirt?
A:s/2=18
B:s plus s=18
C:2s=18
D:2s plus s= 18

See the explanation. :)

Step-by-step explanation:

As a side note, while I know you don't need to solve the problem and just need the equation, I'm going to solve it anyway so you can see how problems like this work so that you can solve them for yourself. :)

As the problem states, the cost of a single shirt (s) and a single pair of pants (p) TOGETHER is $18. It also states that a pair of pants (p) costs twice as much as a shirt (s). This, believe it or not, gives us all the information we need to solve the problem.

Pretty quickly, we can come up with two equations:

2s = p

p + s = 18

Then, through substitution, we find that:

2s + s = 18

Now, that right there is your answer, and you can just stop here to keep going if you'd like. I, however, am going to solve the problem and find the numbers. I implore you to continue reading.

Continuing on:

3s = 18

3s / 3 = 18 / 3

s = 6

Finally, we return to our original two equations to figure out the following:

2(6) = p

12 = p

Finally, we find that s = 6 and p = 12.

-2

7 - 9 = -2

reversed:

-2 + 9 = 7