You need to purchase a new cell phone plan. company a offers 700 minutes of talk time per month but they charge 15 cents for every minute you go over the 700 included minutes. company a will charge you $40 per month for this plan. company b offers 500 minutes of talk time per month, but they charge only 5 cents per minute for exceeding the 500 minutes. company b charges $50 per month for this plan. at what number of minutes per month would both plans charge the same amount?

900 minutes

Step-by-step explanation:

Plan A: 700 free minutes + 15 cents per minute over 700 ($40)

Plan B: 500 free minutes + 5 cents per minute over 500 ($50)

The charges for x minutes (assumed x>700) for plan A will be

40+0.15(x-700)

The charges for x minutes (assumed x>500) for plan B will be

50+0.05(x-500)

To find the value of x where both charges are the same, we equate

40+0.15(x-700)=50+0.05(x-500)

Operating

40+0.15x-105=50+0.05x-25

Simplifying

0.10x=90

x=900 minutes

Both plans would charge the same amount when 900 minutes per month are used

so firstly, we need to isolate the y variables to be able to solve these inequalities. firstly, add 0.5x on both sides of the first inequality and subtract 1.5x on both sides of the second inequality:

now since the slope is positive for the first inequality, this means that the line going upwards belongs to the first inequality, and the line going downwards belongs to the second inequality.

next, since y ≥ in the first inequality, this means that the shaded region will be above the first inequality's line, thus shading regions a and b.

next, since y ≤ in the second inequality, this means that the shaded region is going to be below this line, thus shading regions a and c.

since both lines shade region a, this means that region a is the solution.

step-by-step explanation:

mark brainliest!