X=quarters, y=dimes
7+2x=y
0.25x+0.1y=10.15
we substitute the first equation into the second equation
0.25x+0.1(7+2x)=10.15
0.25x+0.7+0.2x=10.15
0.45x+0.7-0.7=10.15-0.7
0.45x=9.45
0.45x/0.45=9.45/0.45
x=21 quarters
7+2x=y, x=21
7+2(21)=y
7+42=y
y=49 dimes
check: 0.25x+0.1y=10.15 when x=21, y=49
21(0.25)=5.25 in quarters
49(0.1)=4.90 in dimes
5.25+4.90=10.15
Attached is a picture of my answer.
Answer:
b
Step-by-step explanation:
The mean is the average...to find the mean, add up all the numbers, then divide by how many numbers there are.
Example :
ur set of numbers : 1,2,3,4
add up all the numbers and divide by how many there are :
(1 + 2 + 3 + 4) / 4 = 10/4 = 2.5...so 2.5 is ur mean (average)
