Answer:
a+b = 4
Step-by-step explanation:
3(a + b)^2 = 81
(a + b)^2 = 27
a + b = sq rt 27
a + b =
· 
a + b = 3
Answer:
7 of the angles measure 144 degrees each and one angle measures 72 degrees
Step-by-step explanation:
Let
x -----> represent the measures of the seven same-size angles,
x/2 ----> represent the measure of the one that is "two times smaller."
we know that
The sum of internal angles of a polygon can be calculated as:

where
n is the number of sides of the polygon
In this case
n=8 (octagon)
substitute

so
The linear equation that represent this problem is

solve for x

so

therefore
7 of the angles measure 144 degrees each and one angle measures 72 degrees
I think that these ordered pairs would be the answer (-2,-1).
First calculate the slope by change in y over change in x
it’s -0.334
then find y intercept
-6
so all together
-0.334x-6