Answer:
so the answer from paper is DC
Answer:
Step-by-step explanation:

Answer:
x = 45
Step-by-step explanation:
0.4 + x(10%) = 4.9 . . . . . . given
x(10%) = 4.5 . . . . . . . . . subtract 0.4
x = 45 . . . . . . . . . . . . multiply by 10
_____
10 × 10% = 100% = 1
Answer:

Step-by-step explanation:
Expression for the rectangular area and perimeter are, respectively:


After some algebraic manipulation, area expression can be reduce to an one-variable form:


The first derivative of the previous equation is:

Let the expression be equalized to zero:


The second derivative is:

According to the Second Derivative Test, the critical value found in previous steps is a maximum. Then:

The maximum area is:

