Mister Exam
Other calculators
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How to use it?
- Equation:
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Equation x^2=12
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Equation 3^x=81
-
Equation x^2-8x+12=0
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Equation x^6=-(12-8x)^3
- Express {x} in terms of y where:
- -5*x-6*y=-1
- 1*x+6*y=-6
- -5*x+6*y=-8
- -2*x-9*y=10
- Derivative of:
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3^x
- Integral of d{x}:
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3^x
- Graphing y =:
- 3^x
- Sum of series:
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81
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Identical expressions
- three ^x= eighty-one
- 3 to the power of x equally 81
- three to the power of x equally eighty minus one
- 3x=81
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Similar expressions
- 9^x+3*3^x-18=0
- 3^x=243
3^x=81 equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
Given the equation:
$$3^{x} = 81$$
or
$$3^{x} - 81 = 0$$
or
$$3^{x} = 81$$
or
$$3^{x} = 81$$
- this is the simplest exponential equation
Do replacement
$$v = 3^{x}$$
we get
$$v - 81 = 0$$
or
$$v - 81 = 0$$
Move free summands (without v)
from left part to right part, we given:
$$v = 81$$
We get the answer: v = 81
do backward replacement
$$3^{x} = v$$
or
$$x = \frac{\log{\left(v \right)}}{\log{\left(3 \right)}}$$
The final answer
$$x_{1} = \frac{\log{\left(81 \right)}}{\log{\left(3 \right)}} = 4$$
$$3^{x} = 81$$
or
$$3^{x} - 81 = 0$$
or
$$3^{x} = 81$$
or
$$3^{x} = 81$$
- this is the simplest exponential equation
Do replacement
$$v = 3^{x}$$
we get
$$v - 81 = 0$$
or
$$v - 81 = 0$$
Move free summands (without v)
from left part to right part, we given:
$$v = 81$$
We get the answer: v = 81
do backward replacement
$$3^{x} = v$$
or
$$x = \frac{\log{\left(v \right)}}{\log{\left(3 \right)}}$$
The final answer
$$x_{1} = \frac{\log{\left(81 \right)}}{\log{\left(3 \right)}} = 4$$
The graph