Answer:
Billy has $27.51
Explanation:
First let's set up an equation to solve this problem.
Assign a variable to Billy's amount. Let's make it x.
Then we just interpret the problem and solve:
2x - 1.30 = 53.72
+1.30 +1.30
----------------------------
2x = 55.02
(Divide by 2 on both sides)
----------------------------
x = $27.51
2x = Billy's amount doubled
2x - 1.30 = Taking away 1.30 from double Billy's amount
53.72 = Sara's amount