Answer :
J = 14
J = 1/2S + 4 1/2
14 = 1/2S + 9/2....multiply everything by 2 to get rid of fractions
28 = S + 9
28 - 9 = S
19 = S
check...
14 = 1/2S + 9/2......S = 19
14 = 1/2(19) + 9/2
14 = 9 1/2 + 9/2
14 = 19/2+ 9/2
14 = 28/2
14 = 14 (correct)
so the sister is 19 <===
J = 1/2S + 4 1/2
14 = 1/2S + 9/2....multiply everything by 2 to get rid of fractions
28 = S + 9
28 - 9 = S
19 = S
check...
14 = 1/2S + 9/2......S = 19
14 = 1/2(19) + 9/2
14 = 9 1/2 + 9/2
14 = 19/2+ 9/2
14 = 28/2
14 = 14 (correct)
so the sister is 19 <===