Question

Kristen spent $131 on shirts. Fancy shirts cost $28 and plain shirts cost $15. If she bought a total of 7 then how many of each kind did she buy?

Answer 1

1 x + 1 y = 7 .............1
Total value
15 x + 28 y = 131 .............2
Eliminate y
multiply (1)by -28
Multiply (2) by 1
-28 x -28 y = -196
15 x + 28 y = 131
Add the two equations

-13 x = -65
/ -13
x = 5
plug value of x in (1)
1 x + 1 y = 7
5 + y = 7
y = 7 -5
y = 2
y = 2
x= 5 plain shirts
y= 2 fancy shirts