Answer:
To find the sum of an infinite geometric series having ratios with an absolute value less than one, use the formula, S=a11−r , where a1 is the first term and r is the common ratio.
Answer:

Step-by-step explanation:
we know that
An exterior angle of a triangle is equal to the sum of the opposite interior angles.
see the attached figure to better understand the problem
so
∠DEF=∠ECD+∠CDE
substitute the given values

solve for x
Combine like terms

Group terms



Find the measure of angle CDE

substitute the value of x

Answer:
Given
x+y+z=0
⟹x+y=−z
Cubing on both sides
(x+y) 3 =(−z) 3
⟹x 3 +y 3 +3x 2y+3xy 2 =−z 3
⟹x 3 +y 3 +3xy(x+y)=−z 3
⟹x 3+y 3+3xy(−z)=−z 3
⟹x 3 +y 3−3xyz=−z 3
⟹x 3 +y 3 +z 3 =3xyz
Step-by-step explanation:
Hope it is helpful.....
The answer is going to be yes it's rational. hope that helped