Phone company A charges $20 per month plus $.15 per minute used. Phone company B charges $35 per month plus $.10 per minute used. Write and solve an equation to find the number of minutes you must use to have the same cost for both phone palns
20 + .15x = 35 + .10x
To find the number of minutes at which the cost is the same for both phone plans, we need to set up an equation. Let's denote the number of minutes as 'x'.
For Phone company A, the cost would be $20 (monthly charge) plus $0.15 (per minute charge) multiplied by 'x', which can be expressed as:
Cost for Phone company A = $20 + $0.15x
For Phone company B, the cost would be $35 (monthly charge) plus $0.10 (per minute charge) multiplied by 'x', which can be expressed as:
Cost for Phone company B = $35 + $0.10x
To find the number of minutes at which the costs are equal, we can set up the following equation:
$20 + $0.15x = $35 + $0.10x
To solve this equation, we can isolate the variable 'x' by subtracting $0.10x from both sides of the equation:
$0.15x - $0.10x = $35 - $20
Simplifying:
$0.05x = $15
Divide both sides of the equation by $0.05 to solve for 'x':
x = $15 / $0.05
Performing the division:
x = 300
Therefore, you must use 300 minutes for the cost to be the same for both phone plans.