Let d = number of dimes, q = number of quarters
<span>Sally has 20 coins in her piggy bank, so </span>
<span>d + q = 20 </span>
<span>The total amount of money is $3.05. </span>
<span>Use the value of each coin multiplied by its number to get total value </span>
<span>.10d + .25q = 3.05 </span>
<span>multiply everything by 100 to clear the decimal places </span>
<span>10d + 25q = 305 and </span>
<span>d + q = 20 </span>
<span>solve the second equation above in terms of either d or q - lets do d </span>
<span>d = 20 - q </span>
<span>sub that into the first equation </span>
<span>10d + 25q = 305 </span>
<span>10(20 - q) + 25q = 305 </span>
<span>200 - 10q + 25q = 305 </span>
<span>15q = 105 </span>
<span>q = 105/15 = 7 </span>
<span>and from above </span>
<span>d = 20 - q = 20 - 7 = 13 </span>
<span>so, there are 13 dimes and 7 quarters </span>
<span>verify with orig problem </span>
<span>13 + 7 = 20, OK, and $1.30 + $1.75 = $3.05
</span>
Answer:
Option C, The volume of the length cube is 3 times the volume of the smaller cube
Step-by-step explanation:
21.8 / 7.8 = 2.8
the volume of the larger would be 21.8^3 = 10360.23
the volume of the larger would be 7.8^3 = 474.55
Answer: D, 6km/hr.
Step-by-step explanation:
Heather can finish a 12-kilometer race in 2 hours, and now we have to find how many kilometers she can ride/run at in 1 hour.
How many hours can Heather run in 1 hour? To solve that, we can use the equation 12 ÷ 2.
12 ÷ 2 = 6.
Therefore, if Heather keeps her pace constant, then her rate will be 6km/hr, or D.
Substitute -3 to x
(-3)^2 + 4(-3) + 1
9 - 12 + 1
= -2
