# Discrete Math Question

## Homework Statement

I attached the problem as file.

## The Attempt at a Solution

I honestly do not know how to solve this problem. I have a test tomorrow, and this is really the only question that I am having difficulty with. I don't really know what mod means, especially in this context. I have tried to read the textbook, but it being rather convoluted, and me being constrained on time, was really quite futile.

#### Attachments

• Capture.JPG
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tiny-tim
Homework Helper
Hi Bashyboy!

a = 4 (mod 13) means that if you divide a by 13, the remainder is 4

(of course, that's the same as saying a - 4 = 0 (mod 13), ie a - 4 is divisible exactly by 13 )

show us what you get for c = 9a (mod 13)

SammyS
Staff Emeritus
Homework Helper
Gold Member

## Homework Statement

I attached the problem as file.

## The Attempt at a Solution

I honestly do not know how to solve this problem. I have a test tomorrow, and this is really the only question that I am having difficulty with. I don't really know what mod means, especially in this context. I have tried to read the textbook, but it being rather convoluted, and me being constrained on time, was really quite futile.
Here's the attachment:

"I don't really know what mod means ..." and you have a test on this stuff tomorrow?

WOW !