Quantcast XP Math - Forums - View Single Post - Math 12 Assignment - due monday sept 21
View Single Post
Old 09-21-2009   #2
MAS1

 
Join Date: Dec 2008
Posts: 249
Default

Quote:
Originally Posted by jasishappy View Post
I have three questions that I don't get how to complete/start in a math assignment during the logarithm/exponent unit:

here are the three questions (image link) http://img3.imageshack.us/img3/4051/mathassignment.png

please message back if you can help with them
1. (sqrt(a))^3x = (a^(x^2))((a^(1/7))^(-5-2x))
a^(3x/2) = (a^(x^2))(a^(-(5/7)-(2x/7)))
a^(3x/2) = a^(x^2 -(2/7)x -(5/7))
(3/2)x = x^2 -(2/7)x -(5/7)
0 = x^2 -(25/14)x -(5/7)
Use quadratic formula to find x = 2.12 or -0.34

2. 2^(-1) = log9(logx(1/343))
(1/2) = log9(logx(1/343))
9^(1/2) = logx(1/343)
3 = logx(1/343)
x^3 = (1/343)
x = (1/7)
Note: The sqrt(9) = +3 and -3, but we cannot use -3 because it gives us x = 7 and if we plug it back into the original equation then we get log9(-3) which is not defined.

3. I'm not sure about this one.
MAS1 is offline