Reagan (R)
Sara (S)
Lauren (L)
R-3 (Reagan's age 3 years ago...)
we have 3 equations with 3 variables:
R-3 = 3 * (S-3) -> R -3 = 3S - 9 -> R = 3S -6
R-3 = (L-3) / 2 -> 2R -6 = L - 3 -> L = 2R -3
R+3 = 2 * (S+3) -> R +3 = 2S + 6 -> R = 2S +3
3S - 6 = 2S + 3 -> S = 9
R = 2 * 9 +3 = 21
L = 2 * 21 -3 = 39
Reagan is 21
Sara is 9
Lauren is 39
3 years ago - Reagan was 18 - 3 X Sara who was 6
3 years from now - Reagan will be 24 - 2 X Sara who will be 12
