Answer:
- 39 quarters and 41 nickels
Step-by-step explanation:
Let the number of quarters be x and nickels be y.
<u>Given:</u>
- Quarter is 25 cents
- Nickel is 5 cents
- Number of coins is 80
- Total amount is $11.80 = 1180 cents
<u>We have equations:</u>
- x + y = 80
- 25x + 5y = 1180
<u>Solve the system by elimination, subtract 5 times the first equation from the second one:</u>
- 25x + 5y - 5x - 5y = 1180 - 80*5
- 20x = 780
- x = 780/20
- x = 39
<u>Find the value of y:</u>
- 39 + y = 80
- y = 80 - 39y = 41
<u>Verify:</u>
- 25*39 + 5*41 = 975 + 205 = 1180
Answer:
100.34÷2.9=34.6
Step-by-step explanation:
You will need to move the decimal point to the right one place
Answer:
x=5
Step-by-step explanation:
-2<em>x</em> + 6<em>y</em> = -38
3<em>x</em> - 4<em>y</em> = 32
To solve by elimination, multiply the top equation by 3 and the bottom equation by 2.
3(-2<em>x</em> + 6<em>y</em> = -38) --> -6<em>x</em> + 18<em>y</em> = -114
2(3<em>x</em> - 4<em>y</em> = 32) --> 6<em>x</em> - 8<em>y</em> = 64
Add the equations.
-6<em>x </em>+ 18<em>y</em> = -114
6<em>x</em> - 8<em>y</em> = 64
+_____________
0 + 10<em>y</em> = -50
10<em>y</em> = -50
<em>y</em> = -5
Substitute -5 for y into one of the original equations to find x.
3<em>x</em> - 4<em>y</em> = 32
3<em>x</em> - 4(-5) = 32
3<em>x</em> + 20 = 32
3<em>x</em> = 12
<em>x</em> = 4
Check work by plugging the <em>x</em>- and <em>y</em>-values into both of the original equations.
-2<em>x</em> + 6<em>y</em> = -38
-2(4) + 6(-5) = -38
-8 - 30 = 38
38 = 38
3<em>x</em> - 4<em>y</em> = 32
3(4) - 4(-5) = 32
12 + 20 = 32
32 = 32
Answer:
<em>x</em> = 4 and <em>y</em> = -5; (4, -5).
