IDNLearn.com is designed to help you find reliable answers to any question you have. Get the information you need from our community of experts who provide accurate and thorough answers to all your questions.

1. 5 Burgers and 3 orders of fries cost $34. 4 Burgers and 4 orders of fries cost $32. How much does each burger and each order of fries cost?

2. A pile of 44 coins is made up of pennies, nickels, and dimes. If the pile is worth $3.07 and there are twice as many nickels as pennies, how many of each coin does the pile contain?


Sagot :

Answer:

1.

a burger costs $5

an order of fries costs $3

2.

7 pennies

14 nickels

23 dimes

Step-by-step explanation:

x = price of a burger

y = price of a order of fries

5x + 3y = 34

4x + 4y = 32

=>

x + y = 8

x = 8-y

5×(8-y) + 3y = 34

40 - 5y + 3y = 34

-2y = -6

y = $3

x = 8 - 3 = $5

x = number of pennies

y = number of nickels

z = number of dimes

0.01×x + 0.05×y + 0.1×z = 3.07

y = 2x

x + y + z = 44

x + 2x + z = 44

3x + z = 44

z = 44 - 3x

0.01×x + 0.05×2x + 0.1×z = 3.07

0.11×x + 0.1×z = 3.07

0.11×x + 0.1×(44-3x) = 3.07

11x + 10×(44-3x) = 307

11x + 440 - 30x = 307

-19x = -133

x = 7

y = 2×7 = 14

z = 44 - 3×7 = 44 - 21 = 23