Respuesta :
Answer:
There are 9 quarters and 3 nickels
Step-by-step explanation:
problems used: 0.5x+0.25y=3.09
x=y+6
so substitute what x is equal to into the problem
0.5(y+6)+0.25y=3.09 <--------- distribute
0.5y+3+0.25y=3.09 <--------- Combine like terms
0.3y+3=3.09 <----------- Subtract 3 on both sided to get y by itself
0.3y=0.9 <------------ Divide by 0.3 on both sides to get what y is equal to
y=3 <-------- now substitute to find what x is equal to
x=3+6
x=9
Answer:
There are 8 nickels and 14 quarters.
Step-by-step explanation:
Let n and q represent the numbers of nickels and quarters present.
Then q = n + 6 states that there are 6 more quarters than there are nickels.
($0.25)(q) + ($0.05)n = $3.90, in which we substitute n + 6 for q:
($0.25)(n + 6) + ($0.05)n = $3.90
Combining the n terms, we get 0.25n + 0.05n = 3.90 - 0.25*6, or:
0.30n = 3.90 - 1.50, or:
$2.40
n = ----------------------- = 8
0.30
There are 8 nickels and 14 quarters.
Check: 14 quarters comes to $3.50 and 8 nickels to $0.40, and $3.50 + $0.40 sums up to $3.90.