+0

# 6*4^x-13*6^x+6*9^x=0

0
1045
5

6*4^x-13*6^x+6*9^x=0

Guest Jun 3, 2015

#2
+26399
+10

Solutions can be seen more easily from the following:

.

Alan  Jun 3, 2015
Sort:

#1
+91435
+10

Integer solutions are x = + or - 1

http://www.wolframalpha.com/input/?i=6*4%5Ex-13*6%5Ex%2B6*9%5Ex%3D0

Melody  Jun 3, 2015
#2
+26399
+10

Solutions can be seen more easily from the following:

.

Alan  Jun 3, 2015
#3
+91435
0

Thanks Alan

I would not have thought to do that.

How can you tell that there will be another solution as as  $$x\rightarrow -\infty$$   ?

Melody  Jun 3, 2015
#4
+26399
+5

Because, if you look at the original form of the equation, 4-∞ = 0, 6-∞ = 0 and 9-∞ = 0 i.e. each of the terms on the LHS is individually zero.

In that limit my rearranged version of the equation doesn't hold, because a divide by zero would be involved.

.

Alan  Jun 3, 2015
#5
+91435
0

Thanks Alan, that makes sense :)

Melody  Jun 3, 2015

### 16 Online Users

We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details