<PRE><B>Question 1135026</B>
the formula to use is y = m * x + b.


b is the initial charger.
m is the hourly charge.
x is the number of hours.
y is the total cost.


store ABC charges an initial fee of 50 dollars plus 10 dollars for every hour of rental.


the formula for ABC is y1 = 10 * x + 50


store XYZ charges an initial fee of 40 dollars plus 15 dollars for every hour of rental.


the formula for XYZ is y2 = 15 * x + 40


when the total is the same, y1 is equal to y2.


since y1 is equal to 10 * x + 50 and y2 is equal to 25 * x + 40, you get:


10 * x + 50 = 15 * x + 40


subtract 40 from both sides of this equation and subtract 10 * x from both sides of this equation to get:


50 - 40 = 15 * x - 10 * x


simplify to get 10 = 5 * x


solve for x to get x = 2


if you rent the boat for 2 hours, the cost would be the same whether you used ABC or XYZ


when x = 2, ABC cost is 50 + 10 * 2 = 70.


when x = 2, XYZ cost is 40 + 2 * 15 = 70.


your solution is 2 hours.








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