+0  
 
0
135
1
avatar+389 

What is ∑n=16[4(−5)n−1]∑n=16[4(−5)n−1] equal to?

 

Hev123  May 16, 2018

Best Answer 

 #1
avatar+942 
+2

Hey Hev!

 

When n = 1,

 

\(4(-5)^{1-1}=4(-5)^0=4\cdot1=4\)

 

When n = 2, 

 

\(4(-5)^{2-1}=4(-5)^1=4\cdot-5=-20\)

 

When n = 3,

 

\(4(-5)^{3-1}=4(-5)^2=4\cdot25=100\)

 

We can tell there is a pattern with multiplying by -5. 

 

The next three terms in order are -500, 2500, and -12500

 

You add them to find the solution,

 

I hope this helped,

 

Gavin

GYanggg  May 16, 2018
 #1
avatar+942 
+2
Best Answer

Hey Hev!

 

When n = 1,

 

\(4(-5)^{1-1}=4(-5)^0=4\cdot1=4\)

 

When n = 2, 

 

\(4(-5)^{2-1}=4(-5)^1=4\cdot-5=-20\)

 

When n = 3,

 

\(4(-5)^{3-1}=4(-5)^2=4\cdot25=100\)

 

We can tell there is a pattern with multiplying by -5. 

 

The next three terms in order are -500, 2500, and -12500

 

You add them to find the solution,

 

I hope this helped,

 

Gavin

GYanggg  May 16, 2018

24 Online Users

avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.