2 years ago

8

Mathematics

1 answer:

marissa [1.9K]2 years ago

3 0

Answer:

11 pennies

33 nickels

7 quarters

Step-by-step explanation:

Let x be the number of pennies, then the number of nickels is 3x.

There are 51 coins in total, so the number of quarters is 51 - x - 3x = 51 - 4x.

Amounts:

in pennis - x cents;
in nickels - 5(3x) = 15x cents;
in quarters - 25(51 - 4x) cents.

Tota amount = $3.51 = 351 cents.

Hence,

$x+15x+25(51-4x)=351\\ \\x+15x+1,275-100x=351\\ \\x+15x-100x=351-1,275\\ \\-84x=-924\\ \\84x=924\\ \\ x=11$

11 pennies

33 nickels

7 quarters

You might be interested in

you have $200 in a savings account.Each week for 8 weeks, you take out $18 for spending money. How much money is in your account

ivolga24 [154]

Answer:

$56

Step-by-step explanation:

Since you are doing this for 8 weeks, you multiply 8 by 18 and you get 144. You then subtract 144 from 200 and get 56 dollars.

Hope this helped!

7 0

2 years ago

Solving Systems of Equations by substitution<br>-5x-8y=17<br>2x-7y=-17

jarptica [38.1K]

$\left\{\begin{array}{ccc}-5x-8y=17\\2x-7y=-17\end{array}\right\\\left\{\begin{array}{ccc}-5x=8y+17&/\cdot(-2)\\2x-7y=-17&/\cdot5\end{array}\right\\\\\left\{\begin{array}{ccc}10x=-16y-34\\10x-35y=-85\end{array}\right\\\\substitute:\\\\-16y-34-35y=-85\\-51y=-85+34\\-51y=-51\ \ \ \ /:(-51)\\y=1\\\\10x=-16\cdot1-34\\10x=-50\ \ \ \ /:10\\x=-5\\\\Solution:x=-5\ and\ y=1$