Answer:
The concentration of hydrogen ions in moles per liter (M) is 
Step-by-step explanation:
As we know
The hydrogen ion concentration of any solution at pH is given by

Substituting the given values in above equation, we get -
mol/l
The concentration of hydrogen ions in moles per liter (M) is 
Let n = length
let n-4 = width since it is 4 meters shorter
2( n+n-4) =72 Two of the length and width added together equal the perimeter
combine like terms
2(2n -4) = 72 Now use the distributive law on the left side of the equation
4n -8 = 72 Now add 8 to both sides
4n -8 +8 = 72 +8
4n = 80 Finally divide each side by 4
n=20
so the length is 20 and the width is 4 less or 16.
Let's see if our answer works.
20 + 16 + 20 +16 =? 72
72 =72 yes, it does. Length = 20 Width = 16
First find the slope, take derivative of both sides with respect to x.
2y dy/dx=3x^2+6x
solve for dy/dx
dy/dx=[3x^2+6x]/2y
plug in given vales of (1,2(
dy/dx=9/4
now you have everything you need to plug into point slope form
y-2=(9/4)(x-1)
answer is y=(9/4)x+(1/4)
This problem has a slope of 2
7-3. 4
----- = ---. = 2
5-3. 2