Terry and Ed start a lawn mowing business and purchase the mowers and equipment for $1,300. They charge $15 for each lawn and use $2 worth of gas for each job. How many lawns must Terry and Ed mow before breaking even?
Let's say Terry and Ed mow the same number of lawns, which we'll call "x".
The cost of mowers and equipment is $1300.
The total cost of gas for each lawn is (2 * x).
Their total cost is the cost of mowers and equipment plus the cost of gas, which is (1300 + 2 * x).
The total revenue they earn is ($15 * x).
The equation for breaking even is (1300 + 2 * x) = (15 * x).
Simplifying the equation gives 1300 + 2 * x = 15 * x.
Subtracting 2 * x from both sides of the equation gives 1300 = 13 * x.
Dividing both sides of the equation by 13 gives 100 = x.
They must mow 100 lawns before breaking even. Answer: \boxed{100}.