Answer:
The answer is 60°
Explanation:
From looking at the problem we know that mZAOB and mZBOC make up angle mZAOC.
We also know that mZAOC is 104°
This means that the two other angles have to make up 104°
To figure out mZBOC,
First, you can subtract 30 and 42 from 104.
We do this because it allows us to focus on the variables.
104-30-42=32
Next, we can look at the variables and the coefficients and see that in order for 7x and 9x to make 32, x has to equal 2.
7(2)+9(2)=32
Now that we know what x equals we can substitute it into the equation for mZBOC.
9x + 42°
9(2) + 42°
60°
Thus, mZBOC equals 60°