10•8=80
so something times 80 will equal 400
80•5=400
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.
False, it would not make a right triangle
Answer:
Step-by-step explanation:
hello :
(4x+3)(2x-5)=0
4x+3=0 or 2x-5=0
x= -3/4 or x=5/2