Please help! 3 ^ (x/2+1)=12.2?

How can I solve for x

Lilian2012-01-11T06:23:30Z

Favorite Answer

Knowledge of logarithm is needed to solve this equation.
3^(x/2+1) = 12.2
Add lg at both sides,
lg 3^(x/2+1) = lg 12.2
(x/2+1) lg 3 = lg 12.2
(x/2+1) = lg 12.2/lg 3
(x/2+1) = 2.2769
x/3 = 2.2769
x = 2.2769*3
= 6.8307

Jeff Aaron2012-01-11T14:21:15Z

3^((x/2) + 1) = 12.2
(x/2) + 1 = log (base 3) of 12.2
x/2 = (log (base 3) of 12.2) - 1
x = 2*((log (base 3) of 12.2) - 1)
x =~ 2.55381

Or did you mean:
3^(x/(2+1)) = 12.2
3^(x/3) = 12.2
x/3 = log (base 3) of 12.2
x = 3*(log (base 3) of 12.2)
x =~ 6.83

d/dx+d/dy+d/dz2012-01-11T16:54:58Z

let C = 12.2
then with some rearranging you get

x = 2*(ln(C)/ln(3)-1)

x = 2.28