+0  
 
0
45
2
avatar

The terms 140, a, 560 are the first, second and third terms, respectively, of a geometric sequence. If  a is positive, what is the value of a ?

 Oct 23, 2020
 #1
avatar+10583 
+1

The terms 140, a, 560 are the first, second and third terms, respectively, of a geometric sequence. If a is positive, what is the value of a ?

 

Hello Guest!

 

\(a=140\cdot q\\ \color{blue}140\cdot q^2=560\\ q=\sqrt{\frac{560}{140}}\\ q=2\\ a=140\cdot 2\)

 

\(a=280\)

The geometric sequence is 140, 280, 560.

laugh  !

 Oct 23, 2020
 #2
avatar
0

 

The terms 140, a, 560 are the first, second and third terms, respectively, of a geometric sequence. If a is positive, what is the value of a ?   

 

560 is 4 times 140, so I'd expect "a" to be 2 times 140, therefore 280 

   

 Oct 23, 2020

23 Online Users

avatar
avatar