Modulus of any number is always positive because it is the absolute size of the number. That is we disregard any sign it might have. That makes |x|=x and |-x| = x. Similarly |3|=3 and |-3| = 3

But to get the modulus of a negative number we need to multiply the number by -1, for example -1*(-3 )

Hence we can generalise the above finding by saying that to get modulus of positive number (x) we can directly write x while to get the modulus of a negative number we need to multiply by -1*x = -x

Therefore, |x| = {x, if x is positive and -x if x is negative}