Answer:
The equation 1/9•9=1 is justified by the mathematical principle of multiplication identity, which states that any number multiplied by 1 is equal to itself.
Explanation:
In this case, 9/9 = 1, because any number divided by itself equals 1. Therefore, we can rewrite the equation as:
1/9 • 9 = 1/9 • 9/1
Using the associative property of multiplication, we can rearrange the terms as:
(1 • 9)/(9 • 1) = 9/9
Simplifying the left-hand side gives:
9/9 = 1
Therefore, we can conclude that:
1/9 • 9 = 1
So, the equation is justified by the mathematical principles of multiplication identity, division, and associative property of multiplication.