Question

Let x,y \(\in~Z^+\) such that 11|(3x+7y). Which of these must also be divisible by 11?

a. 4x+6y
b. x+y+5
c. 9x+4y
d. 4x - 9y
e. x+y-1

Answer 1

im confused as to why there would only be 1 correct choice

Answer 2

prolly seeing it a little off, might need to run a euclidean/reverse on it to be sure

Answer 3

7 = 3(2) + 1

0
0 1
0-2(1) = -2 ; x' = -2, y' = 1

11 * [3(-2)+7(1)=1]

3(-22)+7(11) = 11
x'' y''

x = x'' + 7n
y = y'' - 3n

Answer 4

not surre too.........