Answer:
, 
Step-by-step explanation:
The equations of volume and surface area are presented below:


The length of the tank is:

The expression fo the surface area is therefore simplified into an univariable form:


The first and second derivatives of the expression are, respectively:


The first derivative is equalized to zero and length of the square side is now found:



![l = \sqrt[3]{\frac{138}{4} }](https://tex.z-dn.net/?f=l%20%3D%20%5Csqrt%5B3%5D%7B%5Cfrac%7B138%7D%7B4%7D%20%7D)

Now, the second derivative offers a criteria to determine if solution leads to an absolute minimum:

(Absolute minimum)
The depth of the tank is:


Answer: 
Step-by-step explanation:
<u>Given the system of equation</u>


<u>Expand the parenthesis of the 1) equation</u>




<u>Current System</u>


<u>Substitute the y value of the 1) equation with the 2) equation</u>

<u>Add ( x² + 4x + 3) on both sides</u>


<u>Combine like terms</u>


<u>Factorize the quadratic equation</u>


<u>Substitute the x values into one of the equations to find the y value</u>



<u>Therefore, the two solutions are:</u>

Hope this helps!! :)
Please let me know if you have any questions
Answer:
Jane has a constant rate of pay because her earnings go up by 12 every unit of time.
Answer:
15y^5
Step-by-step explanation:
Formula for the area of a rectangle is length times width.
so in this case, it would be 15y^5!! Trust me I just did this!
Answer:
x = 80
Step-by-step explanation:
Combine − 3/5x and 7/20x to get -19/20x.
Then combine -19/20x and 1/4x and you get -7/10x.
Then you multiply both sides by -10/7 which is the reciprocal of -7/10.
Make -56(-10) one fraction.
Multiply -56 and -10 and you get 560.
Then divide 560 by 7 to get 80.