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.
</span>
Answer:
12
Step-by-step explanation:
To solve for a side using pythag:

Looks like the very definition for a rational number
<span>Length = x Width = 2x
Perimeter = 2 * length + 2 * width
= 2x + 4x
= 6x
6x = 66
x = 11
</span><span>Length = x Width = 2x
Perimeter = 2 * length + 2 * width
= 2x + 4x
= 6x
6x = 66
x = 11</span>