Answer:
1
Step-by-step explanation:
3x+2y=8
x=2y
3(2y)+2y=8
6y+2y=8
8y=8
y=1
x=2(1)
x=2
x-1=2-1
x-y=1
Answer:
.
Step-by-step explanation:
35 pencils would cost $2.80,
$1.60 / 20 = $.08
Each pencil costs $0.08 each
.08 * 35 = 2.80
So, you need 10 penny, 4 nickles and 7 dimes
Lets, check it.
According to the question,
total coins = 21
7 + 4 + 10 = 21
21 = 21.........................................true
Now,
their value should equal $1.00 = 100 cents
Penny = 1 cent
nickle = 5 cent
dime = 10 cent,
So,
(10 *1) + (4 * 5) + (7 * 10) = 100
10 + 20 + 70 = 100
100 = 100......................................true
So, you need 10 penny, 4 nickle, and 7 dimes
Density = mass / volume
Density = 4,830 / 0.25
Density = 19,320 kg/m