Find the the decimal fraction which when multiplied by itself give 84.64

9.2 and - 9.2 (because when a negative is squared by another negative it becomes positive)

Step-by-step explanation:

The reasoning is that if you multiply a decimal fraction by itself it is known as squaring the given number. So to get the answer you must square root 84.64, which gives you 9.2 or - 9.2.