SOLUTION: How do I do these? Solve the equation 9^x-1=(1/3)^2x Solve the equation 4^3x-1=1.5625x10^-2

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: How do I do these? Solve the equation 9^x-1=(1/3)^2x Solve the equation 4^3x-1=1.5625x10^-2      Log On


   

Question 236404: How do I do these?
Solve the equation 9^x-1=(1/3)^2x
Solve the equation 4^3x-1=1.5625x10^-2
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Solve for x:
9%5E%28x-1%29+=+%281%2F3%29%5E%282x%29 Substitute 9+=+3%5E2
%283%5E2%29%5E%28x-1%29+=+%281%2F3%29%5E%282x%29 Multiply the exponents on the left side.
3%5E%282x-2%29+=+%281%2F3%29%5E%282x%29 Invert the right side and change the sign of the exponent.
3%5E%282x-2%29+=+3%5E%28-2x%29 Now since the bases (3) are equal, the exponents must be equal, so...
2x-2+=+-2x Add 2x to both sides.
4x-2+=+0 Add 2 to both sides.
4x+=+2 Divide both sides by 4.
x+=+2%2F4 Simplify.
highlight%28x+=+1%2F2%29