The multiplicative inverse of a number is the number when you multiply it, it gives you the product of 1.
So for - 27, what number will give us 1 when we multiply it by -27
-27 * -1/27 = 1
So the multiplicative inverse of -27 = -1/27
7/9 * 9/7 = 1
-9/16 * -16/9 = 1
So in essence, just take the number and flip it
-27 = -1 / 27
7/9 = 9/7
-9/16 = -16/9
100 centimeters is equal a meter so you can say 345 centimetres is the same as 3,45 metres
i hope i helped you somehow
