If 3^(6x) = 8100, what is the value of (3^(x-1))^3?
A.90
B.30
C.10
D.10/9
E.10/3
10/3
Ans is 10/3
ans is 10/3
3^6x = 8100
therefore, 3^3x * 3^3x = 90 * 90 from above we can say, 3^3x = 90 ——————————-i
the reqd eqn, is (3^(x-1))^3 => 3^3x – 3^3 => 3^3x/ 27 ——- ii
from i & ii, sub 3^3x, so 3^3x/ 27 = 90/27 =>
10/3 ……… answer E …….
I’ve posted the question from previous GMAT test paper
10/3 3^6x=8100, we get the value of x=100/9 then we substitue the value of x in the other equation. Incase there is any other way of solving this problem please share.
pleas give the explanation of this problem
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10/3
Ans is 10/3
ans is 10/3
3^6x = 8100
therefore, 3^3x * 3^3x = 90 * 90
from above we can say, 3^3x = 90 ——————————-i
the reqd eqn, is (3^(x-1))^3 => 3^3x – 3^3 => 3^3x/ 27 ——- ii
from i & ii, sub 3^3x, so 3^3x/ 27 = 90/27 =>
10/3 ……… answer E …….
I’ve posted the question from previous GMAT test paper
10/3
3^6x=8100, we get the value of x=100/9
then we substitue the value of x in the other equation.
Incase there is any other way of solving this problem please share.
pleas give the explanation of this problem
10/3