At Westonci.ca, we provide reliable answers to your questions from a community of experts. Start exploring today! Get precise and detailed answers to your questions from a knowledgeable community of experts on our Q&A platform. Discover detailed answers to your questions from a wide network of experts on our comprehensive Q&A platform.
Sagot :
let d = number of dimes, q = number of quarters
Sally has 20 coins in her piggy bank, so
d + q = 20
The total amount of money is $3.05.
Use the value of each coin multiplied by its number to get total value
.10d + .25q = 3.05
multiply everything by 100 to clear the decimal places
10d + 25q = 305 and
d + q = 20
solve the second equation above in terms of either d or q - lets do d
d = 20 - q
sub that into the first equation
10d + 25q = 305
10(20 - q) + 25q = 305
200 - 10q + 25q = 305
15q = 105
q = 105/15 = 7
and from above
d = 20 - q = 20 - 7 = 13
so, there are 13 dimes and 7 quarters
verify with orig problem
13 + 7 = 20, OK, and $1.30 + $1.75 = $3.05
Sally has 20 coins in her piggy bank, so
d + q = 20
The total amount of money is $3.05.
Use the value of each coin multiplied by its number to get total value
.10d + .25q = 3.05
multiply everything by 100 to clear the decimal places
10d + 25q = 305 and
d + q = 20
solve the second equation above in terms of either d or q - lets do d
d = 20 - q
sub that into the first equation
10d + 25q = 305
10(20 - q) + 25q = 305
200 - 10q + 25q = 305
15q = 105
q = 105/15 = 7
and from above
d = 20 - q = 20 - 7 = 13
so, there are 13 dimes and 7 quarters
verify with orig problem
13 + 7 = 20, OK, and $1.30 + $1.75 = $3.05
[tex]x-\ amount\ of\ dimes\\\\y-\ amount\ of\ quarters\\\\
\left \{ {{x+y=20} \atop {0,1x+0,25y=3,05\ \ |*(-10)}} \right.\\\\
\left \{ {{x+y=20} \atop {-x-2,5y=-30,5}} \right. \\+-----\\Addition\\\\
-1,5y=-10,5\ \ \ | divide\ by\ -1,5\\\\
y=7\\\\x=13\\\\There\ are\ 7\ quarters\ and\ 13\ dimes.[/tex]
Thank you for trusting us with your questions. We're here to help you find accurate answers quickly and efficiently. We appreciate your visit. Our platform is always here to offer accurate and reliable answers. Return anytime. Thank you for visiting Westonci.ca. Stay informed by coming back for more detailed answers.