Maths
posted by Sanjay .
9^x+2  6* 3^x+1= 0 find x
Answer earlier I got confused

I believe it was Steve who had answered you earlier.
He started by letting u = 3^x
look at the first term 9^(x+2) < I will assume those necessary brackets, as did Steve.
9^(x+2) = (3^2)^(x+2)
= 3^(2x + 4)
= 3^2x * 3^4
= 81 * (3^x)^2 , also 6*3^(x+1) = 6*3^x * 3^1 = 18*3^x
so, 9^(x+2)  6* 3^(x+1) = 0 becomes
81 * (3^x)^2  18*3^x = 0
81 u^2  18u = 0
9u(9u  2) = 0
9u = 0 > u = 0
or
9u = 2 > u = 2/9
so 3^x = 0 , which has no solution
OR
3^x = 2/9
xlog3 = log2  log9
x = (log2  log9)/log3 = appr 1.369
This answer can be verified in the original equation
Respond to this Question
Similar Questions

maths
simultaneous equations x + 2y = 4 3x  4y = 7 x=3 and y = 1/2 i need to explain how i got this answer and do not know how to do that? 
hca 270
hey yea i posted earlier and i havent responded can some one please hel[p im confused and am cutting close on assinment because ive got things going on and mixed up can someone please help this is due tonite help 
MathReiny
I posted this problem earlier and you answered it for me. The teacher said the correct answer is 3+2y/74y. How is that the answer. Below is what you did earlier 3/(y+2) / (7/y4)) = 3/(y+2) * (y4)/7 = (3y12)/(7y+14) or 3(y4)/[7(y+2)] 
Metric System
Hi, Damon helped me with this problem earlier, but im confused on how he got the answer. I really don't understand the math or the mathamatical symbols he used. Would someone maybe explain to me in a different way. E. Coli, a typical … 
grade 9 GEOGRAPHY
I posted a question earlier about the sensitive tourist I am a little confused on what the question is asking exactly. "Sensitve tourist" suggestions so that visitors can minimize their impact on the local environment and community. … 
maths(urgent....please...)
1) A ball is hit at an angle of 36 degrees to the horizontal from 14 feet above the ground. If it hits the ground 26 feet away (in horizontal distance), what was the initial velocity? 
social studies
I need help checking my question. Explain why the Confederacy spared Washington d.c from being destroyed? 
Math
Here is the problem. I got the answer but I would like a better understanding. Find the equation of a line that passes thru(6,2) and is perpendicular to equation x3y+16. I got the final answer being 3x+16. Can someone please explain … 
Maths
Steve  you answered this question earlier for someone else and gave them the formula for how to answer it. I have the same problem in my homework and have used the formula you gave, but have got an answer that does not appear in the … 
Maths
Steve  you answered this question earlier for someone else and gave them the formula for how to answer it. I have the same problem in my homework and have used the formula you gave, but have got an answer that does not appear in the …