Let x and y be integers. Show that 9x + 5y is divisible by 19 if and only if x + 9y is divisible by 19.

Guest Mar 1, 2021

#1**+1 **

if 9x + 5y is divisible by 19 only if x + 9y is divisible by 19, that means that if we subtract them from each other, it should be divisible by 19. to make this simpler, we can multiple x + 9y by 9, so we can remove the x. once we subtract, we get 76, which is divisible by 19. So this means that when one is divisble by 19, the other is as well.

SparklingWater2 Mar 1, 2021