solve: 2^3z+9=8^2z+1

8 answers

2^3z+9=8^2z+1
rearrange things a bit and you have
8^2z - 2^3z - 8 = 0
but 8 = 2^3, so that's just
8^2z - 8^z - 8 = 0
since 8^2z = (8^z)^2, this is just a quadratic equation, so

8^z = (1±√33)/2
Since 8^z is always positive, we have
8^z = (1+√33)/2
z = log8(1+√33)/2
Raise 8 to the power of 2
8z+9=64z+1

Subtract 64z from both sides of the equation which gives us:
8z+9−64z=1

Subtract 64z from 8z which gives us.
−56z+9=1

Move all terms not containing z to the right side of the equation(we subtracted 9):
−56z=−8

Now solve for z!
Oops...I messed up....
and now we see why parentheses are important when doing math online.
in the original problem i just raise all the numbers with powers which got me 8z+9=64z+1
thanks!
oobleck is correct to point out the importance of brackets

Andrea probably meant:
2^(3z+9)=8^(2z+1)
2^(3z+9)=2^(6z+3)
then
3z + 9 = 6z + 3
6 = 3z
z = 2

fiddlestick's solution is bogus
oobleck is correct the way you typed it
well played, Reiny.
You are the brainliest!
Similar Questions
    1. answers icon 1 answer
  1. Combine like terms:-3x^2+2x-4x^2-9+6x-2x^2+8 Solve for x: 8x-11= -11x+18 Solve for x: -2(x-5)+7=z-8-5x Solve for x: (x-2)/5 -
    1. answers icon 8 answers
  2. Solve the indicated variable:1. Volume of a cone: solve for h: V=¨ir^2h/3 2. Temperature formula: solve for C: F=9/5C+32
    1. answers icon 1 answer
  3. Put in the correct orderSolve exponentiation. Solve multiplication and division. Solve operations within parentheses Solve
    1. answers icon 1 answer
more similar questions