Question 136374
let Jennifer's age=x+4
her sister's age=x 
(x+4)+4=2(x-5)
x+8=2x-10
x-2x=-10-8
-x=-18
x=18 which is the sister's age now.
18+4=22 Jennifer's age now.
proof
22+4=2(18-5)
26=2*13
26=26