This is the answer I calculate .If the answer is wrong, I am sorry about this
Answer:



Step-by-step explanation:
Given
Represent each withe first letter of their name;
So:


--- the average of books
Required
The number of book each has
Substitute
,
in 

Multiply both sides by 3


Take LCM and solve


Multiply both sides by 2/9










2p=p(1+0.14)^t
2=1.14^t
t=log(2)/log(1.14)=5.29 years
Answer:
angle X is equal to 130 degree
Step-by-step explanation:
angle sum prop in septagin is 900 degree
so 900-770 is 130