SOLUTION: 3^(x2-12) = 9^(2x) someone PLZ help Im stuck on this ONE question!!!

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: 3^(x2-12) = 9^(2x) someone PLZ help Im stuck on this ONE question!!!      Log On


   

Question 458539: 3^(x2-12) = 9^(2x) someone PLZ help Im stuck on this ONE question!!!
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
3%5E%28x%5E2-12%29+=+9%5E%282x%29...write 9 as 3%5E2

3%5E%28x%5E2-12%29+=+3%5E2%282x%29+

3%5E%28x%5E2-12%29+=+3%5E%284x%29+........if bases are same then exponents are same too

so, you have:

x%5E2-12=4x.......solve for x

x%5E2-4x-12=0..replace -4x with -6x%2B2x

x%5E2-6x%2B2x-12=0.....group

%28x%5E2-6x%29%2B%282x-12%29=0

x%28x-6%29%2B2%28x-6%29=0

%28x%2B2%29%28x-6%29=0

solutions:

x%2B2=0.........->....x=-2

x-6=0.......->....x=6