Answer:

Step-by-step explanation:
--- sides





Required
The measure of B
The interior angles of a polygon is:

So, we have:



The measure of B is calculated using:

Substitute known values

Collect like terms


Collect like terms


We need more to answer the question I think
Answer:
This system has infinite solutions and it would be much easier to solve it by elimination but substitution it is.
Step-by-step explanation:
-3x+3y=9
-x+y=3
Isolate either x or y in any of the equations. I'll go with the second.
y = 3+x
Now substitute this for y in the first equation.
-3x+3(3+x)=9
Distribute the 3
-3x+9+3x=9
Combine like terms:
9=9
0=0
It's infinite
100/66655*61364=<span>92.0621108694%</span>