Answer:
See Below.
Step-by-step explanation:
We want to show that the function:

Increases for all values of <em>x</em>.
A function is increasing whenever its derivative is positive.
So, find the derivative of our function:
![\displaystyle f'(x) = \frac{d}{dx}\left[e^x - e^{-x}\right]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20f%27%28x%29%20%3D%20%5Cfrac%7Bd%7D%7Bdx%7D%5Cleft%5Be%5Ex%20-%20e%5E%7B-x%7D%5Cright%5D)
Differentiate:

Simplify:

Since eˣ is always greater than zero and e⁻ˣ is also always greater than zero, f'(x) is always positive. Hence, the original function increases for all values of <em>x.</em>
Area = length *width
A = x²
3x² = (x+10)(x+12)
3x² = x²+10x+12x+120
3x² = x²+22x+120
3x²-3x² = x²+22x+120-3x²
0 = -2x²+22x+120
Factor to solve for x:
-2(x²-11x-60)
(x+4)(x-15)
x = -4 & x = 15 but we can't have a negative length so we eliminate 4. The length of the square is 15 cm.
Answer:
(n+6)-(n-10)
Step-by-step explanation:
n is the number.
plus means addition
minus means subtraction
The correct answer is option D
The solution is shown below: