Write and Solve Systems of Equations The sum of two numbers is 20.5: x + y = 20.5
Their difference is 6.5: x − y = 6.5

x = 13.5 and y = 7

Step-by-step explanation:

Given equations are :

x + y = 20.5 ...(1)

x − y = 6.5 ...(2)

Add equation (1) and (2).

x + y + x- y = 20.5+6.5

2x = 27

x = 13.5

Put the value of x in equation (1).

13.5 + y = 20.5

y = 20.5-13.5

y = 7

Hence, the values of x and y are 13.5 and 7.

29 is the correct answer

step-by-step explanation:

x= cost per bracelet

number of bracelets * x + shipping charge = total cost

so

9x+9=72