Kristin spent $131 on shirts. fancy shirts cost $28 and plain shirts cost $15. she bought seven total shirts. how many fancy and fancy and plain shirts did kristin buy?

The number of plain shirts bought is 5 and number of fancy shirts bought is 2

Let number of plain shirts bought be "a"

Let number of fancy shirts bought be "b"

Given that Kristin bought seven total shirts

plain shirts bought + fancy shirts bought = 7

a + b = 7 eqn 1

Also that Kristin spent $131 on shirts and Fancy shirts cost $28 and plain shirts cost $15

15a + 28b = 131   eqn 2

Multiply first equation by 28 to eliminate b:

28a + 28b = 196   eqn 3

subtracting eqn 2 from eqn 3

28a + 28b = 196

15a + 28b = 131

(-)

13a = 65

a = 5

Substitute a = 5 in eqn 2

15(5) + 28b = 131

75 + 28b = 131

28b = 56

b = 2

Thus the number of plain shirts bought is 5 and number of fancy shirts bought is 2