Answer:
(x-7) (x+4)
Step-by-step explanation:
x^2 - 3x - 28
What two numbers multiply to -28 and add to -3
-7*4 = -28
-7+4 = -3
(x-7) (x+4)
Let's use a formula in order to find how much the interior angles are supposed to add up to.
(n-2)×180; n is the number of angles.
(5-2)×180= 3×180=540
We need for the interior angles to add up to 540. Let's make an equation.
100+102+108+121+x=540
431+x=540; let's find x.
540-431= 109
So, X= 109°
Answer: 96°
180-84 = 96
I hope this is good enough: