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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Steps 4 and 5 are being used to get the equation in step 6.
Steps 5 and 7 are being used to get the equation in step 8.
Steps 8 and 6 are being used to get the equation in step 9.
In step 14, "similar argument" means to draw segment BD and follow the same logic in steps 3-12.
Answer: -10x+7.5
Step-by-step explanation:
First multiply -2.5(4x)= -10x and then -2.5x-3= 7.5 it should be -10x+7.5
Answer:
Length, l = 11 ft.
Width, w = 9 ft.
Step-by-step explanation:
From the given data, the area of the rectangle = 99 ft².
Area of the rectangle = Length, l X Width, w
Here, Length, l = 7 more than twice the width
⇒ Length, l = 7 + 2w
Therefore, Area, A = 99 = (7 + 2w)w
⇒ 99 = 7w + 2w²
⇒ 2w² + 7w - 99 = 0
Solve the Quadratic equation using the formula: x = 
for the quadratic equation ax² + bx + c = 0.
Therefore, w = 
Since, 
we get:
This gives two values of 'w', viz., w = 
, 
⇒ w = 
, -9.
We take the integer values.
If w = -9, then l = 2(-9) + 7
⇒ l = - 18 + 7 = - 11
Therefore, the length, l of the rectangle = - 11 ft.
and the width, w of the rectangle = - 9 ft.
Hence, the answer.
Answer:
225/4
Step-by-step explanation:
x²– 15x – 23 = 0
To complete the square
We take to coefficient of the x term
-15
divide by 2
-15/2
Square it
225/4
Add it to each term
