Help with 1,3 or u can just do whichever .

one hamburger costs $3

One hot dog costs $2.5

Step-by-step explanation:

1) Let x represent the price of one hamburger.

Let y represent the price of one hot dog.

Tim bought 3 hamburgers and 4 hot dogs for $19. It means that

3x + 4y = 19- - - - - - - - - - - - -1

John bought 5 hamburgers and 2 hot dogs for $20. It means that

5x + 2y = 20- - - - - - - - - - - - -2

Multiplying equation 1 by 5 and equation 2 by 3, it becomes

15x + 20y = 95

15x + 6y = 60

Subtracting, it becomes

14y = 35

y = 35/14

y = 2.5

Substituting y = 2.5 into equation 1, it becomes

3x + 4 × 2.5 = 19

3x + 10 = 19

3x = 19 - 10 = 9

x = 9/3

x = 3

2) Let x represent the price for one belt.

Let y represent the price for one hat.

He bought 6 belts and 8 hats for $86. This means that

6x + 8y = 86 - - - - - - - - - - - -1

At the same price, he bought 9 belts and 8 hats for $101. This means that

9x + 8y = 101 - - - - - - - - - - - -2

Subtracting equation 2 from equation 1, it becomes

- 3x = - 15

x = - 15/-3

x = 5

Substituting x = 5 into equation 1, it becomes

6 × 5 + 8y = 86

30 + 8y = 86

8y = 86 - 30

8y = 56

y = 56/8

y = 7

Each belt costs $5

Each hat costs $7

4

step-by-step explanation:

he spend 5.1 minutes chatting with his friends.

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5.1