Question

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

Answer 1

Answer:

9.) $t=.05m+20$

10.) $t=.10m+5$

11.) $300$ 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:

$t=.05m+20$

Substitute your values for #10:

$t=.10m+5$

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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.

$.10m+5=.05m+20$

Let's subtract $5$ from both sides of the equation:

$.10m=.05m-15$

Subtract $.05m$ from both sides of the equation:

$.05m=15$

Divide by the coefficient of $m$, in this case: $.05$

$m=300$

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Let's substitute $200$ minutes into both of our original models from questions 9 & 10 to see which one the person should choose (the cheaper one).

Company A:

$t=.05(200)+20$

Multiply.

$t=10+20$

Add.

$t=30$

Company B:

$t=.10(200)+5$

Multiply.

$t=20+5$

Add.

$t=25$