A troubling exponential equation...
Nova Roma
16-05-2005, 22:13
(3^2x) + 2(3^x) = 15
My teacher won't give us the method to do it, and she insists that we aren't trying hard enough; however, no matter what I do I keep on getting 15/4 as the answer. The real solution is 1.
Reformentia
16-05-2005, 22:19
(3^2x) + 2(3^x) = 15
My teacher won't give us the method to do it, and she insists that we aren't trying hard enough; however, no matter what I do I keep on getting 15/4 as the answer. The real solution is 1.
(3^2x) + 2(3^x) = 15
(3^2x) + 2(3^x) -15 = 0
((3^x)+5)((3^x)-3) = 0
3^x = -5 or 3.
No value of x will make 3^x = -5 . Only x=1 will make 3^x=3.
x=1.
Light Keepers
16-05-2005, 22:32
It seems many of us were ready to answer your problem instantly, but then saw the second post. Your problem has been solved several times over I'd wager. :rolleyes:
Reformentia
16-05-2005, 22:38
It seems many of us were ready to answer your problem instantly, but then saw the second post. Your problem has been solved several times over I'd wager. :rolleyes:
Hehehe.... fastest keyboard in the west...
Nova Roma
16-05-2005, 22:55
Of course, something so simple as factoring... Argh! Thanks.