Jessica is selling books during the summer to earn money for college. She earns a commission on each sale but has to pay for her own expenses.
After a month of driving from neighborhood to neighborhood and walking
door-to-door, she figures out that her weekly earnings are approximately a
linear function of the number of doors she knocks on.
She writes the equation of the function like this: E(x) = 10x - 30, where x is the
number of doors she knocks on during the week and E(x) is her earnings for
the week in dollars.
Which of the following are reasonable interpretations of the y-intercept of
Jessica's function?
Check all that apply.
A. She can earn $10 per week even if she does not knock on any
doors
B. Her expenses are $30 per week.
c. If she does not knock on any doors at all during the week, she will
lose $30
D. She will lose $10 per week if she does not knock on any doors.

C. if 10x is the door she have to knock so the -30 is how much she will earn during the week and if she doesn't knock any then she will lose the whole $30 dollars . sorry i can't explain myself good but i think it is so

B and C (took the test)

Step-by-step explanation:

B. Her expenses are $30 per week

C. If she does not knock on any doors at all during the week, she will lose $30.

answer: ratio of volume of cone (with 3 times the height and equal diameter) to volume of cylinder is 2 to 1. the value of π is not used.

step-by-step explanation:

radius is diameter/2 = 4.

area of circle is π r^2.

volume of cylinder is height × area of base = hπr^2 = 3(4^2) π = 48π cubic inches.

not knowing the formula for volume of cone, i calculate it using calculus (which is for calculating things).

volume of cone is integral 0 to h area(y) dy. area(y) is π r(y)^2. r(y) runs r to zero as y runs zero to h, r(0) = r, r(h) = 0.

r(y) = r - r/h y

area(y) = π (r - r/h y)^2 = π (r^2 - 2r^2y/h + r^2y^2/h^2) = π r^2(1-2y/h+y^2/h^2)

antiderivative area(y) = π r^2 (y-y^2/h+y^3/(3h^2))

integral 0 to h = π r^2(h-h^2/h+h^3/(3h^2) - (0)) = π r^2(h - h + h/3) = π r^2(h/3) = π/3 r^2 h

volume of this cone is π/3(4^2)18 cubic inches.

= 6 16 π = 96π cubic inches.

cone has twice the volume, 96/48.

cone height is 6 times the cylinder.

ratio of volume formula: π r^2 cancels.

cone over cylinder ratio is 6h/3 to h, 2 to 1.