C=1500+4x where x is cds, C is cost
R=10x where R is revenue
then, P=R-C
P=10x-1500-4x
P=6x-1500
set P=0
1500=6x
x=250
check, C=1500+4*250, R=10*250
C=250, R=250
They need to sell 250 cds before they make profit
Answer:
(-8,-3)
Step-by-step explanation:
This question is similar to the vertex form of a quadratic equation, so you can think of this equation like f(x) = (x-h)+k. Using this equation, you can determine the vertex (h,k) of |x+8|-3, which is (-8,-3).
The gradient of the perpendicular line would be the negative reciprocal of the original line. Therefore the gradient of the perpendicular line would be -2/5x.
Since we know y=mx+c, ∴y=-2/5x+c. Sub in the x and y values of the given point and we get that c=26/5.
The perpendicular equation would be y=-2/5x+26/5.
I hope I got this right.
Answer:
12.63 km/hr
Step-by-step explanation:
Given the distance=240km
At 12 km/hr it will take =240/12 =20
time for Express train = 20-1=19
speed=240/19=12.63...km/hr
Answer:
227750
Step-by-step explanation:
If we assume that the rate of increase in population is linear, then in 4 years the increase in population is (224000 - 221000) = 3000.
So, the rate of increase in population is 
persons per year.
Now, we have to calculate the population of the town after an additional 5 years.
So, the population in 5 years will increase by (750 × 5) = 3750
Therefore, the population after an additional 5 years will be (224000 + 3750) = 227750. (Answer)
