Problema Solution

Your friend bought a total of 8 shirts and jeans as gifts for $135. The price per shirt was $12 and the price per jeans was $25. Write and solve an equation to find how many shirts and how many pair of jeans your friend bought

Answer provided by our tutors

Let


'x' be the number of shirts bought then the total money spent on shirts will be 12 * x

'y' be the number of jeans bought then the total money spent on jeans will be 25 * y


x + y = 8 (the total of jeans and shirts is 8)

12*x + 25*y = 135 (the total money spent for all the gifts)


Lets solve the equations to find x and y. Notice that x and y must be non-negative.


From x + y = 8 we can write x = 8 - y and substitute in 12*x + 25*y = 135:


12* (8 - y) + 25*y = 135

96 - 12*y + 25*y = 135

96 + 13*y = 135

13*y = 135 - 96

13*y = 39

y = 39/13


y = 3 jeans


x = 8 - y = 8 -3 = 5 shirts


My friend bought 3 pairs of jeans and 5 shirts.