kelly takes pam shopping for new clothes. shirts cost $12 and pants cost $21. Pam spends a total of $240 on 14 new items. how many shirts and how many pants did she buy?

Let’s call the amount of pants x and the amount of shirts y.
12y + 21x = 240
y + x = 14 which could be changed to x= 14-y

now you plug it into the first equation
12y + 21 (14 - y) = 240
12y + 294 - 21y = 240

add the similar terms
12y - 21y = 240 - 294
-9y = -54

cancels the minus signs on both sides
9y = 54
y= 6

now you plug y = 6 into the equation x = 14-y
x = 14 - 6
x = 8

Pam bought 8 pants and 6 shirts