Answer:

Step-by-step explanation:

Answer:
(x²+3x-88) square units
Step-by-step explanation:
Area of a rectangle = Length × Width
Given
length of a rectangle is (x-8)units
Its width is (x+11) units.
Required
Expression for the area of the rectangle
Substituting the given function into the formula.
Area of the rectangle = (x-8)(x+11)
Area of the rectangle = x(x)+11x-8x-88
Area of the rectangle = x²+3x-88
Hence the expression that represents the area of the rectangle is x²+3x-88 units²
Answer:
I need more information
Step-by-step explanation:
Answer:

divide through out by -8 :

Answer is b
Answer:
- Base Length of 68cm
- Height of 34 cm.
Step-by-step explanation:
Given a box with a square base and an open top which must have a volume of 157216 cubic centimetre. We want to minimize the amount of material used.
Step 1:
Let the side length of the base =x
Let the height of the box =h
Since the box has a square base
Volume 

Surface Area of the box = Base Area + Area of 4 sides

Step 2: Find the derivative of A(x)

Step 3: Set A'(x)=0 and solve for x
![A'(x)=\dfrac{2x^3-628864}{x^2}=0\\2x^3-628864=0\\2x^3=628864\\x^3=314432\\x=\sqrt[3]{314432}\\ x=68](https://tex.z-dn.net/?f=A%27%28x%29%3D%5Cdfrac%7B2x%5E3-628864%7D%7Bx%5E2%7D%3D0%5C%5C2x%5E3-628864%3D0%5C%5C2x%5E3%3D628864%5C%5Cx%5E3%3D314432%5C%5Cx%3D%5Csqrt%5B3%5D%7B314432%7D%5C%5C%20x%3D68)
Step 4: Verify that x=68 is a minimum value
We use the second derivative test

Since the second derivative is positive at x=68, then it is a minimum point.
Recall:

Therefore, the dimensions that minimizes the box surface area are:
- Base Length of 68cm
- Height of 34 cm.