Question

If 4^(2-X)=3, then 4^(2x-1)=?

Answer 1

6.9

Answer 2

Thanks but how did you get it? :)

Answer 3

x=7.111111

Answer 4

Hi but can you explain it? Thanks!

Answer 5

Break up the power.
\[4^{2-x} = 4^{2} * 4^{-x} = 3\]
\[4^{-x} = 3/16\]
Take the log base 4 of each side.
-x = -1.206
x = 1.206

Checking, \[4^{2-1.206} = 3.006\] So the x value is valid.

Plugging in x for the other equation, \[4^{2(1.206) -1} = 7.08 = 7.1\]

If you use the EXACT value, you get 7.1111...

Answer 6

64/9=7.1111

Answer 7

you can also use logarithm

Answer 8

Yes, you could take the log base 4 of each side right away, but I did not know if he/she was used to polynomials as a power, so I decided to break up the power.

Answer 9

we can also try
If 4^(2-X)=3, then 4^(2x-1)=?
log4^(2-X)=log3
(2-X)log4=log3
(2-X)=log3/log4
2-(log3/log4)=x now use this to the other eq
4^(2x-1)=?
4^[(2(2-log3/log4)-1)]=?
=64/9=7.11111 ans

Answer 10

whews my pc hanged on me....lol

Answer 11

anyway, the answer to both is correct she/he can choose whatever they doing at school............. lol