Solve for x in the exponential equation: 22x−9⋅2x+8=02^{2x} - 9 \cdot 2^x + 8 = 0

Answer: The solutions for xx are 00 and 33.

Step-by-step solution

Step 1: Rewrite the equation

We can rewrite the term 22x2^{2x} as (2x)2(2^x)^2 using the exponent rule (am)n=amn(a^m)^n = a^{mn}. This helps us see a pattern in the equation.

Step 2: Substitute to form a quadratic equation

To simplify the equation, we can substitute yy for 2x2^x. This transforms the exponential equation into a standard quadratic equation in terms of yy.

Step 3: Factor the quadratic equation

We need to find two numbers that multiply to 8 and add up to -9. These numbers are -1 and -8. So, we can factor the quadratic equation as (y−1)(y−8)=0(y - 1)(y - 8) = 0.

Step 4: Solve for y

For the product of two factors to be zero, at least one of the factors must be zero. This gives us two possible values for yy: y=1y=1 or y=8y=8.

Step 5: Substitute back and solve for x

Now we substitute back 2x2^x for yy. For 2x=12^x = 1, we know that any non-zero number raised to the power of 0 is 1, so x=0x=0. For 2x=82^x = 8, since 8=238 = 2^3, we have x=3x=3.

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