Answer:
The Cost of yellow shirts is $15 and the cost of purple shirt is $ 60
Step-by-step explanation:
Let cost of one yellow shirt be x
and the cost of one purple shirt be y
On Monday
5x + 7y = 165--------------------(1)
On Tuesday
4x + 11y = 213----------------------(2)
To solve (1) and (2)
multiplying eq(1) with 4
20x + 28y = 660--------------------(3)
multiplying eq(2) with 5
20x + 55y = 1056-------------------(4)
Subtracting (3) from (4)
20x + 55y = 1056
20x + 28y = 660
(-)
-----------------------------------
0x +27y = 405
-----------------------------------
y = 15
Substituting y value in eq(1)
5x + 7(15) = 165
5x + 105 =405
5x =405 -105
5x =300
x = \frac{300}{5}
x =60