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4.4^x+4/4^x=10 solve​

User Ignis
by
8.1k points

1 Answer

2 votes

Answer:

x = -1/2, +1/2

Explanation:

You want the solution to the exponential equation ...

4·4^x +4/4^x = 10

Solution

Let z = 4^x. This makes the equation ...

4z +4/z = 10

Multiplying by z gives the quadratic ...

4z² +4 = 10z

2z² -5z +2 = 0 . . . . . . subtract 10z, divide by 2

(z -2)(2z -1) = 0 . . . . . factor

The solutions to this are ...

z = 2 and z = 1/2

Values of x

Using the relation between x and z, we have ...

z = 4^x

2^1 = 2^(2x) . . . . . . . . for z = 2 and 4 = 2^2

1 = 2x . . . . . . . equating exponents

x = 1/2

And for z = 1/2, we get ...

2^-1 = 2^(2x)

-1 = 2x

x = -1/2

The solutions are x = -1/2 and x = 1/2.

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Additional comment

If you really want the solutions to 4.4^x +4/4^x = 10, you can find them by graphing and/or iteration. There are no algebraic methods for the solution of this sort of equation.

They are approximately x ≈ −0.632119785543 and x ≈ 1.52048985866.

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4.4^x+4/4^x=10 solve​-example-1
User Gpoo
by
8.2k points