1.2x + 3.4 = 10.6
subtract 3.4 from each side
1.2x = 7.2
divide each side by 1.2
x = 6
T_n = 3 * T_(n-1)
Long way (always works!)
T_5 = 3*T_4,
T_4 = 3*T_3
T_3 = 3*T_2
T_2 = 3*T_1
T_5 = 3*3*3*3*T_1 = 81*T_1 = 81*8 = 648!
Short way (sometimes it works!)
T_n = 3^(n-1) * T_1 (this case is a geometric series of ratio-=3)
T_5 = 3^4*8 = 648
Let Sara weight =x+25
amber wiegh =x
x+25+x=205
x= 90
Sara weight is 90+25= 115
