Question 260350
eah is twice her sister age decreased by 4
translates to
(i) L = 2S - 4
the two ages together add up to 89
translates to
(ii) L + S = 89
by substitution, we get
(iii) 2S-4 + S + 89
3S - 4 = 89
3S = 93
S = 31
L = 58