After 3.2 or 3 hours and 12 minutes, the total cost of services is equal. Explanation: First, set up equations for total cost for both Happy Paws and Woof Watchers. x= number of hours y= total cost Happy Paws y = 1.5 x + 19 Woof Watchers y = 2.75 x + 15 Because you have to find when total cost is equal, then the y's of both equations are equal to each other. That means you can substitute the Woof Watchers' 2.75 x + 15 into the y of Happy Paws. 2.75 x + 15 = 1.5 x + 19 Rearrange the equation so the variable, x, is on one side and the numbers on the other and solve. 1.25 x = 4
x = 3.2 You can check the answer by plugging 3.2 into x in the two equations and see if they yield the same total cost Happy Paws: 1.5 ( 3.2 ) + 19 = 23.8