Let P = number of coins of pennies (1 penny = 1 cent)
Let N = number of coins of nickels (1 nickel = 5 cents)
Let D = number of coins of dimes (1 dime = 10 cents)
Let Q = number of coins of quarters (1 quarter = 25 cents)
a) P + N + D + Q = 284 coins, but P = 173 coins, then:
173 + N + D + Q =284 coins
(1) N + D + Q = 111 coins
b) D = N + 5 OR D - N =5 coins
(2) D - N = 5 coins
c) Let's find the VALUE in CENTS of (1) that is N + D + Q = 111 coins
5N + 10D + 25 Q = 2,278 - 173 (1 PENNY)
(3) 5N + 10D + 25Q = 2105 cents
Now we have 3 equation with 3 variables:
(1) N + D + Q = 111 coins
(2) D - N = 5 coins
(3) 5N + 10D + 25Q = 2105 cents
Solving it gives:
17 coins N ( x 5 = 85 cents)
22 coins D ( x 10 = 220 cents)
72 coins D ( x 25 = 1,800 cents)
and 173 P,
proof:
that makes a total of 85+2201800+172 =2,278 c or $22.78
The price of a baseball is $3.75. This problem can be solved using an elimination between two equation with two variables in it which are, 5x + 3y = 23.75 and 2x + 7y = 31.25. First, multiply the first equation by 2 and the second equation by 5 which resulting in 10x + 6y = 47.5 and 10x + 35y= 156.25 and then eliminate the x variable resulting in 29y = 108.75. The baseball price can be acquired from this equation (y = 3.75) because y variable represents the baseball price.
First off, if you divide $960/$8, you will get 120 “sets” of payment. Multiply this value by the amount of money Jenny is responsible for paying and the amount her parents are responsible for paying to find their total contributions.
a. Jenny will have to pay $600
b. Jenny’s parents will contribute $360 to her new laptop.
