R=-1/800(x^2-2400x)
use R'=0
R'=1/400x-300, 1/400x=300 => x=1200 critical point
take R(1200), we know its max bcuz of the orientation of R
Answer:
The answer is 5:12
Step-by-step explanation:
It is 5:12 because We already know that 7 pens are blue. To find the number of red pens we must subtract 12 - 7 and get 5 as the number of red pens. Now knowing the no. of red pens and total number we can say the ratio of red pens to total no. is 5:12
Answer:
three-fifths over three-eights equals one and three-fifths miles per hour
Step-by-step explanation:
- The martinez family walked three over five of a mile; this means they walked 3/5 of a mile.
- They walked such distance in in three over eight of an hour, this means 3/8 of an hour.
To find the rate in miles per hour, we have to divide 3/5 divided 3/8.

TO make division of fraction, we must invert the second fraction and multiply them:

The ratio is 8/5 miles per hour. In the answer given it is expressed as a mixed numer 1 3/5 that is equal to 8/5.
To transform a fraction to a mixed number, you have to divide numerator by denominator. Explanation is in figure attached.