solve 4^2x+1 = 8 .....mathematics help?
回答 (8)
2009-05-24 9:02 am
✔ 最佳答案
There are two possibilities1)
4^(2x) + 1 = 8
Add -1 both sides
4^(2x) = 7
Takin log both sides
2x(log4) = log7
x = log7/2*(log4) = 0.8451/1.2041
OR x = 0.7018
2)
4^(2x + 1) = 8
(2^2)^(2x + 1) = 2^3
2^[2(2x + 1)] = 2^3
2(2x + 1) = 3
2*2x + 2*1 = 3
4x = 3 - 2
x = 1/4
OR x = 0.25
2009-05-23 4:46 pm
4^(2x+1) = 8 (put log at both side so that you can solve it)
log 4^(2X+1) = log 8
(2x+1) log 4 = log 8
2x + 1 = log 8 / log 4 = 1.5
2x + 1 = 1.5
2x = 1.5 -1 = 0.5
x = 0.5 / 2 = 0.25
log 4^(2X+1) = log 8
(2x+1) log 4 = log 8
2x + 1 = log 8 / log 4 = 1.5
2x + 1 = 1.5
2x = 1.5 -1 = 0.5
x = 0.5 / 2 = 0.25
2009-05-26 3:38 am
Question is unclear.
Will assume that you mean :-
4^(2x + 1 ) = 8
2^(4x + 2) = 2^3
4x + 2 = 3
4x = 1
x = 1/4
Will assume that you mean :-
4^(2x + 1 ) = 8
2^(4x + 2) = 2^3
4x + 2 = 3
4x = 1
x = 1/4
2009-05-23 6:16 pm
The other answers are right if its 4^(2x+1).
But if its 4^(2x) +1, they are not. So be careful about typing the correct problem when you post a difficulty here.
But if its 4^(2x) +1, they are not. So be careful about typing the correct problem when you post a difficulty here.
2009-05-23 4:42 pm
4^(2x + 1) = 8
(2^2)^(2x + 1) = 2^3
2^[2(2x + 1)] = 2^3
2(2x + 1) = 3
2*2x + 2*1 = 3
4x = 3 - 2
x = 1/4 (0.25)
(2^2)^(2x + 1) = 2^3
2^[2(2x + 1)] = 2^3
2(2x + 1) = 3
2*2x + 2*1 = 3
4x = 3 - 2
x = 1/4 (0.25)
2009-05-23 4:39 pm
4^2x+1 = 8
We know that 4 = 2^2 and 8 = 2^3 so
2^2(2x+1) = 2^3
Therefore, by equating the powers
2(2x+1) = 3
2x+1 =3/2
2x = 3/2 -1 = 1/2
x=1/4
We know that 4 = 2^2 and 8 = 2^3 so
2^2(2x+1) = 2^3
Therefore, by equating the powers
2(2x+1) = 3
2x+1 =3/2
2x = 3/2 -1 = 1/2
x=1/4
2009-05-23 4:26 pm
If the question is
4^(2x+1) = 8 then this is how you go
We know 4 = 2^2 and 8 = 2^3 so
2^2(2x+1) = 2^3
Therefore
2(2x+1) = 3
2x+1 =3/2
2x = 3/2 -1 = 1/2
x=1/4
4^(2x+1) = 8 then this is how you go
We know 4 = 2^2 and 8 = 2^3 so
2^2(2x+1) = 2^3
Therefore
2(2x+1) = 3
2x+1 =3/2
2x = 3/2 -1 = 1/2
x=1/4
2009-05-23 4:23 pm
4^2x+1 = 8 => 2^(4x+2) = 2^3 => 4x+2 = 3 => x = 1/4.
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