I know how to solve this, but what is this kind of equation called, where can I find more equations like this to practice with?
Thanks!
3^(7-2x)=1/27 what is x?
2009-06-03 3:56 pm
回答 (6)
2009-06-03 4:02 pm
✔ 最佳答案
This is an exponential equation since you are solving for the exponent and the answer you get is the argument.Other examples of this would be this:
2^x = 8
4(7 - x) = 16
2009-06-03 11:02 pm
3^(7-2x)=1/27
1/27=1/(3)^3 [note: a^(-m)=1/a^m]
=3^(-3)
so3^(7-2x)=1/27
=3^(-3)
bases are equal, so powers can be equated.
7-2x= -3
7+3=2x
2x=10
x=10/2
x=5
1/27=1/(3)^3 [note: a^(-m)=1/a^m]
=3^(-3)
so3^(7-2x)=1/27
=3^(-3)
bases are equal, so powers can be equated.
7-2x= -3
7+3=2x
2x=10
x=10/2
x=5
2009-06-03 11:00 pm
look for exponential equations.
2009-06-03 11:18 pm
3^(7 - 2x) = 1/27
3^(7 - 2x) = 1/(3^3)
3^(7 - 2x) = 3^(-3)
7 - 2x = -3
-2x = -7 - 3
x = -10/-2
x = 5
3^(7 - 2x) = 1/(3^3)
3^(7 - 2x) = 3^(-3)
7 - 2x = -3
-2x = -7 - 3
x = -10/-2
x = 5
2009-06-03 11:06 pm
3^(7-2x)=1/27
(7-2x) log (3) = log(1/27)
(7-2x) log(3) = -log(27)
(7-2x) log(3) = - log(3^3)
(7-2x) log(3) = -3 log(3)
divide both sides by log(3)
7-2x=-3
-2x=-10
x=5
(7-2x) log (3) = log(1/27)
(7-2x) log(3) = -log(27)
(7-2x) log(3) = - log(3^3)
(7-2x) log(3) = -3 log(3)
divide both sides by log(3)
7-2x=-3
-2x=-10
x=5
2009-06-03 11:02 pm
linear, it can be solved and graphed. since x can change this moves the points up and down on the graph.
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