[8000/6=1333,3;10000/6=1666,6] [10000/6=1666,6;30000/6=5000] [60000/6=10000;70000/6=11666,6]
<span>(3 2/3-1 2/7*5 4/9):(-2.5)=
1 2/7*5 4/9=9/7*49/9=7
3 2/3-7=-3 1/3
-3 1/3*(-2.5)=-10/3*(-5/2)=25/3=8 1/3
</span>(8x+2,4):3=1.8
8х+2.4=1.8*3
8х+2.4=5.4
8х=5.4-2.4
8х=3
х=3:8
х=3/8