Jim ordered a sports drink and three slices of pizza for $8.50. his friend ordered two sports drink and two slices of pizza for $8.00. applying system of equations

Step-by-step explanation:

Let d and p represent the costs of a drink and a pizza slice, respectively. The two orders have a value ...

  d + 3p = 8.50

  2d + 2p = 8.00

Subtracting the second equation from twice the first gives ...

  2(d +3p) -(2d +2p) = 2(8.50) -(8.00)

  4p = 9.00 . . . . . simplify

  p = 2.25 . . . . . . divide by 4

Solving the first equation for d and putting in the value, we have

  d = 8.50 -3p = 8.50 -3·2.25 = 8.50 -6.75

  d = 1.75

The cost of a drink is $1.75; the cost of a pizza slice is $2.25.

answer: the anser is 3

step-by-step explanation:

c- 2o is equal to 9

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9