What is the additive and multiplicative inverse of 0.4?

1 Answer
Feb 6, 2015

The answers are: #-0.4and2.5#

The inverse of 0.4 in the additive operation is that element (#a#) that added to 0.4 gives 0.

So:

#0.4+a=0rArra=-0.4#

The inverse of 0.4 in the multiplicative operation is that element (#a#) that multiplied to 0.4 gives 1.

So:

#0.4*a=1rArr4/10a=1rArr2/5a=1rArra=5/2=2.5#.