Answer:
I'm not 100% sure I'm right but I think x = -1
because it says "f(x)" and then it says"Find f(-1)" so that is why I think x = -1

Solution:
Given equation is
.
To solve the equation by step by step.
Step 1: Given

Step 2: Combine like terms together.
Plus symbol changed to minus when the term goes from right to left (or) left to right of the equal sign.

Step 3: Subtract the fractions in the left side.

⇒ 
Step 4: Divide both side of the equation by 3, we get


Hence, the answer is
.
Given:
The sum of two terms of GP is 6 and that of first four terms is 
To find:
The sum of first six terms.
Solution:
We have,


Sum of first n terms of a GP is
...(i)
Putting n=2, we get


...(ii)
Putting n=4, we get



(Using (ii))
Divide both sides by 6.
Taking square root on both sides, we get

Case 1: If r is positive, then using (ii) we get
The sum of first 6 terms is




Case 2: If r is negative, then using (ii) we get
The sum of first 6 terms is




Therefore, the sum of the first six terms is 7.875.
<h2>Please write ur question properly</h2>