Question

Solve. 64x = 16x – 1

a. x = –2
b. x = –1
c. x = -1/4
d. x = -1/3

Answer 1

64x = 16x -1
48x = -1
x=-1/48

Are you sure the choices or problem is correct?

Answer 2

OH! Sorry.

64^x=16^(x-1)

Answer 3

AH!

Ok to solve for a variable in the exponent, you want to change both sides to having the same base. So you want a common factor between 64 and 16. Which would be? :)

Answer 4

4?

Answer 5

You could use 4; you could also use 8. We'll do it your way :)

So 4 to what power gets 64? and 4 to what power gets 16?

Answer 6

64/4 is 16 and 16/4 is 4.

Answer 7

4^3 = 64. I was meaning the exponent; not division :)

SO it would look like this 4^3x = 4^(2x-2)

Then you can set 3x=2x-2
and solve for x=-2 :)

does that make sense?

Answer 8

Yep! Thanks!

Answer 9

Great :) anytime!