after buying some tickets for $19.00, Ann has $18.00 left. How much money did Ann have to beginwith

After buying some tickets for $19.00, Ann has $18.00 left. How much money did Ann have to begin with?

Let the beginning amount be b. We're given:
b - 19 = 18. <-- We subtract 19 because a purchase is a spend reducing the original amount

To solve for b, we type the equation b - 19 = 18 into our search engine and we get:
b = 37