1)y=7,2-2,4х
2,4х=7,2-у
1. при у=1
2,4х=7.2-1
2,4х=6,2
х=6,2/2,4
х=3
2. при у=-1
2,4х=7,2+1
2,4х=8,2
х=8,2/2,4
х=41/12=3 5/12
3. при у=-2/3
2,4х=7,2+2/3
2,4х=7 3/5
2,4х=7,6
х=4
4.при у=5
2,4х=7,2-5
2,4х=2,2
х=11/12
2)у=2/3+6х
6х=у-2/3
1.6х=1/3
х=1/3:6
х=1/3*1/6=1/18
2.6х=-1 2/3
х=-5/3:6=-5/3*1/6=-5/18
3. 6х=-1 1/3
х=-4/3*1/6=-2/9
4. 6х=4 1/3
х=13/3*1/6=13/18
3)у=-3/8х+7,5
3/8х=у-7,5
1. 3/8х=-6,5
х=-13/2*8/3=-104/6=-53/3=-17 2/3
2. 3/8х=8,5
3/8х=17/2
х=17/2*8/3
х=68/3
х=22 2/3
3. 3/8х=-2/3-15/2
3/8х=-49/6
х=-49/6*3/8
х=-147/48
х=-3 3/48
х=-3 1/16
4. 3/8х=-2,5
х=-5/2*8/3
х=-40/5
х=-8