Step-by-step explanation:
Given line is passing through the points (3, 60) & (6, 50)
Therefore, slope of line:

Answer:
Substitution Property
Step-by-step explanation:
So we know that:

And we also know that:

And by using a specific property, we get that:

Essentially, we <em>substituted</em> B for A.
So, this is an example of the substitution property, where if two sides/angles are congruent, we can substitute them for each other.
19 + (11+37) = (19 + 11) + 37
Associative property of addition