If $\log_8x=\frac{4}{3}y$log8x=43y then the expression $\log_2\left(64x^6\right)$log2(64x6) can be rewritten as: $\log_2\left(64x^6\right)=a+by.$log2(64x6)=a+by. What are the values for a and b?
First, you want to look at Equation #1. Multiply both sides by 3 so that you can get rid of the denominator on the right-hand side. Using the log laws by multiplying the exponent ( $\log_b\left(M^n\right)=n\log_bM$logb(Mn)=nlogbM ), you can change the left hand side of the equation to
$3\log_8x=4y$3log8x=4y
$\log_8x^3=4y$log8x3=4y .
To find x from the first equation, you can rearrange the equation to
$8^{4y}=x^3$84y=x3 since -- if you recall from the beginning of the exponent and logs unit -- $\log_by=x$logby=x is the inverse of $x^b=y$xb=y .
8 is the same as $2^3$23 , so you can rewrite the left-hand side of the new equation again to raise both sides to the third power.
$2^{3\cdot4y}=x^3$23·4y=x3
You can cancel out the powers of 3 by writing the cube roots of $2^{3\cdot4y}$23·4y and $x^3$x3 so that you get
$2^{4y}=x$24y=x . Now that you found x, you can plug this into the second equation.
Now, look at the second equation
$\log_2\left(64x^6\right)=a+by$log2(64x6)=a+by .
You can rewrite the left-hand side as
$\log_264+\log_2x^6=a+by$log264+log2x6=a+by using the log law for which $\log_b\left(M\cdot N\right)=\log_bM+\log_bN$logb(M·N)=logbM+logbN .
Furthermore, you can rewrite $\log_2x^6$log2x6 as $6\log_2x$6log2x .
6 years ago
Answered By Adham R
log23 X= 4/3y
log2 X= 4/3y*3=4y
log2(64x6)=log2(64)+log2(x6)=log2(64)+6*log2(x)=log2(64)+6*4y=6+24y
a=6
b=24
6 years ago
Answered By Sophia E
You have two equations to deal with:
1) $\log_8x=\frac{4}{3}y$log8x=43 y
2) $\log_2\left(64x^6\right)=a+by$log2(64x6)=a+by
First, you want to look at Equation #1. Multiply both sides by 3 so that you can get rid of the denominator on the right-hand side. Using the log laws by multiplying the exponent ( $\log_b\left(M^n\right)=n\log_bM$logb(Mn)=nlogbM ), you can change the left hand side of the equation to
$3\log_8x=4y$3log8x=4y
$\log_8x^3=4y$log8x3=4y .
To find x from the first equation, you can rearrange the equation to
$8^{4y}=x^3$84y=x3 since -- if you recall from the beginning of the exponent and logs unit -- $\log_by=x$logby=x is the inverse of $x^b=y$xb=y .
8 is the same as $2^3$23 , so you can rewrite the left-hand side of the new equation again to raise both sides to the third power.
$2^{3\cdot4y}=x^3$23·4y=x3
You can cancel out the powers of 3 by writing the cube roots of $2^{3\cdot4y}$23·4y and $x^3$x3 so that you get
$2^{4y}=x$24y=x . Now that you found x, you can plug this into the second equation.
Now, look at the second equation
$\log_2\left(64x^6\right)=a+by$log2(64x6)=a+by .
You can rewrite the left-hand side as
$\log_264+\log_2x^6=a+by$log264+log2x6=a+by using the log law for which $\log_b\left(M\cdot N\right)=\log_bM+\log_bN$logb(M·N)=logbM+logbN .
Furthermore, you can rewrite $\log_2x^6$log2x6 as $6\log_2x$6log2x .
$\log_264=6$log264=6 and
$6\log_2x=6\log_2\left(2^{4y}\right)=\left(6\cdot4y\right)\log_22$6log2x=6log2(24y)=(6·4y)log22 .
$\log_22=1$log22=1 , so you're left with $6\cdot4y=24y$6·4y=24y .
Your final answer for the values of a and b are:
$a=6$a=6 and $b=24$b=24 .
Hope this helps!
6 years ago
Answered By Becky L
Change log8x=$\frac{4}{3}y$43 y to exponential function, we have
8 4/3 y=x
(23)4/3 y=x
24y=x
log2(64x6)
= log2(26x6)
=log2(2x)6
=6log2(2x)
=6(log22 + log2x)
=6(1+log2x) since log22=1
=6(1+log224y) substituting x=24y from above
=6(1+4ylog22)
=6+24y
so a=6 and b=24