E^2x -2e^x -8=0 => e<span>^(2x) -2e^x -8=0
Temporarily replace e^x with y.
Then (y)^2 - 2y - 8 = 0. Factors are (y-4) and (y+2).
Roots are y = 4 and y= -2.
Now remembering that we temporarily replaced e^x with y, we let
y=4 = e^x. We need to solve for x. Taking the natural log of both sides, we get:
ln 4 = x (answer)
We have to discard the other root (y= -2), because we cannot take the ln of a negative number.
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Answer:
8/ 25
Step-by-step explanation:
hope it helps!
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11.6 because the square root of 135 is 11.61885.... and when you check it is approximately 135 because 11.6 *11.6 = 134.56, which can be rounded to 135