If 3^6x = 8,100, what is the value of [3^x – 1]^3 ?
A. 90
B. 30
C. 10
D. 10/3
E. 10/9
(D)
My thoughts:
[spoiler]I Simplifieid 3^6x = 27^3x. The other side, to 27^3-3
So 8100^-3 ?
Sorry - a little lost. [/spoiler]
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susamleesmith
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1.3^6x = 8,100 equals to (3^3x)^2=8100doclkk wrote:If 3^6x = 8,100, what is the value of [3^x – 1]^3 ?
A. 90
B. 30
C. 10
D. 10/3
E. 10/9
(D)
My thoughts:
[spoiler]I Simplifieid 3^6x = 27^3x. The other side, to 27^3-3
So 8100^-3 ?
Sorry - a little lost. [/spoiler]
2.Take the square root of both sides.Then you will have this (3^3x)=90
3.[3^x – 1]^3 equals to (3^3x) / 3^3
4.Instead of (3^3x) put 90 in the 3 line
5.You will have 90/27 .After simplification you will get D=10/3
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doclkk
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Very helpfulsusamleesmith wrote:1.3^6x = 8,100 equals to (3^3x)^2=8100doclkk wrote:If 3^6x = 8,100, what is the value of [3^x – 1]^3 ?
A. 90
B. 30
C. 10
D. 10/3
E. 10/9
(D)
My thoughts:
[spoiler]I Simplifieid 3^6x = 27^3x. The other side, to 27^3-3
So 8100^-3 ?
Sorry - a little lost. [/spoiler]
2.Take the square root of both sides.Then you will have this (3^3x)=90
3.[3^x – 1]^3 equals to (3^3x) / 3^3
4.Instead of (3^3x) put 90 in the 3 line
5.You will have 90/27 .After simplification you will get D=10/3
So its 90/27 because 3^-3 = 1/27 right
doclkk wrote:If 3^6x = 8,100, what is the value of [3^x – 1]^3 ?
A. 90
B. 30
C. 10
D. 10/3
E. 10/9
(D)
My thoughts:
[spoiler]I Simplifieid 3^6x = 27^3x. The other side, to 27^3-3
So 8100^-3 ?
Sorry - a little lost. [/spoiler]
[3^x – 1]^3
is different from 3^[(x-1)^3].
People are requested to type properly and hence not to cause head crunching situation to others.
