Math question - which is true/?

Question

which is true;

1. if x is divisible by 3, then x2 is divisible by 3 (x squared)

2. if x2 is divisible by 3, then x is divisible by 3

why?

Answer 1

(1) is true no matter what

(2) is true as long as x is an integer.

Answer 2

Both are correct.

Answer 3

i think they are both true!

Answer 4

1 is true, 2 is not necessarily true

1. if x is divisible by 3, then we can say x = 3n, where n is an integer  

x^2 = (3n)^2 = 9n^2, which is divisible by 9, and therefore divisible by 3

2.  if x^2 is divisible by 3, then we can say that x^2 = 3n

x = sqrt(3n), which is only divisible by 3 sometimes

example that works:

x^2 = 81

x = 9 (both divisible by 3)

example that doesn't work:

x^2 = 27

x = 3sqrt(3)

Answer 5

basically you've asked a question regarding a factor of 3.........

consider two integers either +ve or -ve say for eg 3 and 9

9 is divisible by 3;whereas 3 is not divisible by 9;

therefore 1 is true