Please help

Question

9.a local cellular company has a cellphone plan that costs $32 per month and $0.15 per minute when you talk on the phone.
A)write a monthly for the monthly cost. Y of this plan if you talk x minutes.
B)find the y intercept of the equation. Explain the meaning of the y intercept in the context of the cellphone plan.
C)how much would a 25 minute call cost? How many minutes could you speak for if you spent $39.35?
D)graph equation of the line and label axes.

10.mohammad's financial aid stipulates that his tuition cannot exceed $1500.if his local community college charges a $75 fee registration fee plus $215 per course. What is the greatest number of courses Mohammed can register for? Express the problem as an inequality before solving.
A)identify variables
B)write your equation
C)solve equation
D)state solution

11.Jamal has decided that the best coffee is 48% caffeinated. He cannot find a bag of coffee with this caffeine level.however he purchases a bag that is 40% caffeinated and a bag that is 52%caffeinated.

A)identify variables
B)write your equation
C)solve equation
D) state solution

12.a student had two part time jobs. One pays $9 per hour and the other $12 per hour.between the two jobs the student needs to earn at least $450 per week.
A)write an inequality that shows the number of hours that student can work at each job.
B)graph the inequality, Label axes.

13.the earth is approximately 33,900,000 miles from Mars. What is the distance to Mars in meters given that 1mile =1.61×10 meters? Express the answer in scientific notation to two decimal places.

Answer 1

I only have time for question 9, so here goes:

part a: 

base cost = $32

let x represent the number of minutes used

let y represent the total cost (a function of the number of minutes used

total cost = base cost + 0.15(minutes used)

write this in slope intercept form:

        y = 0.15x + 32

 

part b:

        the y- intercept is 32. This is the cost you would have to pay even if you used no minutes.  Graphically speaking, it represents the point (0,32)

 

part c:

        if the question is asking for the total monthly total cost of the phone when you used 25 minutes,

you substitute 25 for x and solve for y.

                       y = 0.15(25) + 32

         if they just want to know the cost of the minutes alone, it would be .15(25)

part d:

graph the equation with the number of minutes on the x-axis and total cost on the y-axis.  Start at point (0,32) and move up 0.15 and to the right 1(rise over run)

 

hope this helps