Which of the following values of x and y are solutions of the system of inequalities shown below?
x + 3y < 16
x+y > 10

Step-by-step explanation:

You can just check the values:

A.  x = 2, y = 8

x + 3y = 2 + 3×8 = 26 not <16  ⇒  NOT these values

B.   x = 9, y = 2

x + 3y = 9 + 3×2 = 15  <16

x + y = 9 + 2 = 11  >10

YES, x = 9, y = 2 are solutions of the  system of inequalities

C.  x = 1, y = 5

x + 3y = 1 + 3×5 = 16 not <16  ⇒  NOT these values

D.  x = 7, y = 2

x + 3y = 7 + 3×2 = 13  <16

x + y = 7 + 2 = 9 not >10  ⇒  NOT these values

x= cost per bracelet

number of bracelets * x + shipping charge = total cost

so

9x+9=72