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:
7
Step-by-step explanation: (dont trust me)
x^2 + (7)x +18
x(x + 4) + 3(x + 6)
Answer:
1245
Step-by-step explanation:
You have to multiply 415 and 3, since 10 x 3 = 30
415 x 3 = 1245
Answer:
f(x) > 0 over the interval 
Step-by-step explanation:
If f(x) is a continuous function, and that all the critical points of behavior change are described by the given information, then we can say that the function crossed the x axis to reach a minimum value of -12 at the point x=-2.5, then as x increases it ascends to a maximum value of -3 for x = 0 (which is also its y-axis crossing) and therefore probably a local maximum.
Then the function was above the x axis (larger than zero) from 
, until it crossed the x axis (becoming then negative) at the point x = -4. So the function was positive (larger than zero) in such interval.
There is no such type of unique assertion regarding the positive or negative value of the function when one extends the interval from to -3, since between the values -4 and -3 the function adopts negative values.
