Hello,
1-2-1=(1-1)-2=-2=1
Hi,
consider the field
The composition table should look like:
0+0=0
0+1=1+0=1
0+2=2+0=2
1+1=2
1+2=2+1=0
2+2=1
0*0=0=0*1=0*2=1*0=2*0
1*1=1
1*2=2*1=2
2*2=1
No I have the case that I have to calculate:
1-2-1=?
I guess it would be zero but I am not sure
How to do this?
Thank you for helping
greetings
Adding the inverse.
Yes, you normally would have to write 1+(-2)+(-1), but this is now how it was stated.
And for simplification, you directly write 1-2-1.
What I did was not using any commutativity of the subtraction. 1-2-1 becoming 1-1-2 is the commutativity of the addition. It's just that it's simplified and not written 1+(-1)+(-2)
After that, it's still associativity, for addition. For the same reasons.