Answer:
17
Step-by-step explanation:
Let e represent Eric's age now. The problem statement tells us ...
1/4(e -1) + 3(e +1) = 58
(3 1/4)e +2 3/4 = 58 . . . . simplify
13/4e = 55 1/4 . . . . . . . . . subtract 2 3/4
e = (4/13)(221/4) = 221/13 = 17 . . . . . multiply by 4/13
Eric is 17.