a) { x/2+y/2=1 1/3 /x6 x/3-y/2=2 1/3 /x6 3x+3y=8 +2x-3y=14 ------------- 5x=22 x=4,4 y=1 11/15 b) { x+2/5 - 2y=5 /x5 x- y+2/6=3 /x6 5x+2-10y=25 6x-6y+2=18 5x-10y=23 /x6 6x-6y=16 /x-5 30x-60y=138 -30x+30y=-96 -------------- 30y=42 y=1,4 x=7,4 c) { x+y/2-x/3=4 /x6 x-y/2+y/3=-3 /x-6 4x+3y=24 -6x+y=18 /x-3 4x+3y=24 18x-3y=-54 -------------------- 22x=-30 x=-1 8/22 y=6 6/33
x/2+y/2=1 1/3 x/3-y/2=2 1/3 ½x+½y=1⅓ /*6 ⅓x-½y=2⅓ /*6 3x+3y=8 2x-3y=14 3x+3y=8 +2x-3y=14 _____________ 5x=22 x=4,4 y=1 11/15 b) x+2/5 - 2y=5 /*5 x- y+2/6=3 /*6 5x+2-10y=25 6x-6y+2=18 5x-10y=23 /x6 6x-6y=16 /x-5 30x-60y=138 -30x+30y=-96 ____________ 30y=42 y=1,4 x=7,4 c) x+y/2-x/3=4 /x6 x-y/2+y/3=-3 /x-6 4x+3y=24 -6x+y=18 /x-3 4x+3y=24 18x-3y=-54 _______________ 22x=-30 x=-1 8/22 y=6 6/33
