# Math Help - modular arithmetic

1. ## modular arithmetic

Hi,

Could someone please confim if [17.5]18 is the correct answer to the question as it seems wrong.

Thanks

2. ## Change name: Modular arithmetic

Could a moditrator please change the name of the post to

Modular arithmetic

3. Hello,
Originally Posted by 1234567
Hi,

Could someone please confim if [17.5]18 is the correct answer to the question as it seems wrong.

Thanks
What does $[17.5]_{18}$ mean ???

You can see that 7 and 13 are inverse modulo 18.
So the expression is now $13 \times 2+7 \times 7=[75]_{18}=[3]_{18}$

4. Originally Posted by Moo
Hello,

What does $[17.5]_{18}$ mean ???

You can see that 7 and 13 are inverse modulo 18.
So the expression is now $13 \times 2+7 \times 7=[75]_{18}=[3]_{18}$
Yh i made a mistake when caluculating. I just done the working out again and got the same answers.

Thanks for the help.