Question

solve the equation. Separate by commas, if more than one answer.
x^(2)9^(x)-2x9^(x)=3(9^(x))

Answer 1

\[x ^{2}9^{x}-2x9^{x}=3(9^{x})\]

Answer 2

Do this...

Answer 3

Bring over the right-hand side and take out the common factor of 9^x. You have\[9^x(x^2-2x-3)=0\]

Answer 4

That means

Answer 5

either \[9^x=0\]or\[x^2-2x-3=0\]

Answer 6

There is no x here that will make 9^x zero (if you plot any exponential function, you'll see that it never crosses below the x-axis)

Answer 7

Thanks a lot for explaining the steps, much appreciated.

Answer 8

But,\[x^2-2x-3=(x+1)(x-3)\]so your second factor has that\[(x+1)(x-3)=0 \rightarrow x=-1,3\]

Answer 9

No worries.

Answer 10

feel free to become a fan ;)

Answer 11

I will! :)

Answer 12

how do I become a fan though?

Answer 13

There should be a blue link next to my name...says, "Become a fan"

Answer 14

nice, very nice