BRAINLIEST..........show expressions too<333

9.)

10.)

11.) minutes of calling would make the two plans equal.

12.) Company B.

Step-by-step explanation:

Let t equal the total cost, and m, minutes.

Set up your models for questions 9 & 10 like this:

total cost = (cost per minute)# of minutes + monthly fee

Substitute your values for #9:

Substitute your values for #10:

__

To find how many minutes of calling would result in an equal total cost, we have to set the two models we just got equal to each other.

Let's subtract from both sides of the equation:

Subtract from both sides of the equation:

Divide by the coefficient of , in this case:

__

Let's substitute minutes into both of our original models from questions 9 & 10 to see which one the person should choose (the cheaper one).

Company A:

Multiply.

Add.

Company B:

Multiply.

Add.

between 30 and 40 years old

Step-by-step explanation:

in the graph the y axis ($75) meet with the ages between 30 and 40 on the x-axis