Answer:
3x-10=65
Explanation:
So, since he used the coupon, you can do 65+10=75.
The cost before the coupon is 75.
The cost of each shirt is 75/3, but that doesn't solve the question.
You can do (assume each shirt's cost is x)
3x-10=65
I could give more in depth but I can't see the options, sorry!