12) A X equation x-10 = (110-x)+10ax = 65, B 45.
13) Adjust the x equation 52+X=2(38-X) from two people to one person X=8 people.
15) hunter x equation 2X+4( 160-X)=390 hunter X= 125 dog 35
17) time x equation (45-20)X= 15 takes X=0.6 hours.
18) motorcycle speed x equation (X-30)*9=30*3 motorcycle speed X=40 (km/h)
19) Distance to supermarket x
Ab140 x = 70 (1200-x)+90 (1200-120-x) x = 604.
Ac140 x = 70 (1200-x)+90 (1200+120-x) x = 676.