Step-by-step explanation:
We're going to be evaluating if we can round 2. (Values in the 10's place)
The value in the 'ones' place has to be greater than or equal to 5 in order to round up 2.
Since 8 is greater than 5, we can round up 2.
<u>Rounded answer:</u>
38830
Answer:

Step-by-step explanation:

a. is <u><em>Substitution Property</em></u>
b. might be <u><em>definition of supplementary angles</em></u>