We can get the Profit function P(x) from the Hint.
the Profit function is: P(x) = xp(x) - C(x) = -0.00041 x2 + 4x - 600
Attention: don't get confuse by the <span>big P of the profit with the small p of the price</span> To calculate the maximum profit, we need to find the derivative of P(x) then set it to 0 then find x: dP(x)/dx = -0.00082 x + 4 = 0 , so x = 4/0.00082 = 4,878 copies each month.
Answer: rate of train A = 120 km/h
rate of train B = 101 km/h
Step-by-step explanation:
Let x = the speed of train A
Let y = the speed of train B
One train travels 19 km/h slower than the other. Let train B be the slower train. Therefore,
x = y + 19 - - - - - - - - - -1
Recall
Speed = distance/time
Distance = speed × time
If they meet in 3 hours, it means that train A has travelled a distance of
x × 3 = 3x km
And train B has travelled a distance of y × 3 = 3y km
Train A and Train B were 663 kilometers apart when they left their respective destinations. They left at the same time and travelled towards each other. This means that if they meet in 3hours time, they must have covered a total of 663 km. Therefore,
3x + 3y = 663 - - - - - - - - - 2
Substituting x = y + 19 into equation 2, it becomes
3(y + 19) + 3y = 663
3y + 57 + 3y = 663
6y + 57 = 663
6y = 663 - 57 = 606
y = 606/6 = 101 km/h
x = y + 19 = 101 + 19
x = 120 km/h
Answer:D.
Step-by-step explanation:
yards to feet equals 0.3 repeating
Pounds to ounces equals 0.0625
Gallons to pints equals 0.125
Centimeters to millimeters equals 0.1
So d is the right answer
