O A B C D E
×----/------/------/------/------/------
0 1 2 3 4 5
O(0)
A(1)
B(2)
C(3)
D(4)
E(5)
OA=1
OB=2
OC=3
OD=4
OE=5
AB=1
AC=2
AD=3
AE=4
BC=1
BD=2
BE=3
CD=1
CE=2
DE=1
1) 3.3a+a-4=4.3a-4
<span>2) 5a-0.7a-8=4.3a-8
</span><span>3) 5.3b-2b-3=3.3b-3
</span><span>4) 9.6b+7-0.4b=9.2b+7
</span><span>5) 2c-9+5.1c=7.1c-9
</span><span>6) -5c+13-6c=13-11c</span>