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Ok... the equation is 4^2b-3=8^1-b

What is the value of b?

-3/7

7/9

9/7

10/7

2007-12-26 10:58:01 · 5 answers · asked by Anonymous in Science & Mathematics Mathematics

5 answers

4 = 2^2
8 = 2^ 3
4^(2b-3) = 2^(4b-6)
8^(1-b)=2^(3-3b)
4b-6 = 3-3b
7b= 9
b = 9/7

2007-12-26 11:01:59 · answer #1 · answered by lhvinny 7 · 1 0

Let's use a logarithmic expression to solve for 'b'. Let's use a logarithm with a base of '2'.

Now, after taking the logarithm base 2 of both sides we get:

(2b - 3)log (base 2) of 4 = (1-b)log (base 2) of 8

The answer to the logarithmic expression on the left side of the above equation is the integer '2', and on the right side of the above equation is the integer '3'. This is because 2 squared equals 4 and 2 cubed equals 8, where squared means 2 to the second power and 2 cubed means 2 to the third power.

Now, we have (2b - 3)*2 = (1 - b)*3

This a simple algebraic expression now.

4b - 6 = 3 - 3b

Add '3b' and the integer '6' to both sides of the equation:

7b =9

Divde both sides of the equation by the integer '7' and the result is 9/7.

2007-12-26 19:07:01 · answer #2 · answered by Anonymous · 0 0

7

2007-12-26 19:00:47 · answer #3 · answered by legolou2004 2 · 0 0

9/7

4 is 2^2 and 8 is 2^3... if you reduce 4 and 8 to 2 and multiply the exponents by 2 and 3, respectively, you can solve the exponents for b as though it was a normal algebraic equation.

2007-12-26 19:04:04 · answer #4 · answered by hay hayyyy 1 · 0 0

[02]
4^(2b-3)=8^(1-b)
2^2(2b-3)=2^3(1-b)
2^(4b-6)=2^(3-3b)
Now as the base on the both sides are equal,the expnents must be equal
4b-6=3-3b
4b+3b=3+6
7b=9
b=9/7 ans

2007-12-26 19:11:00 · answer #5 · answered by alpha 7 · 0 0

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