Answer:
Step-by-step explanation:
P=2l+2w
28=2l+2w
2l=2w-28
l = (2w-28)/2
l =2(w-14)/2
l = w-14
Is there another part to your question
Answer:
18 stars
Step-by-step explanation:
We can use a ratio to solve
9 stars x
--------- = -----------
2 hearts 4 hearts
Using cross products
9*4 = 2x
36 = 2x
Divide by 2
36/2 =2x/2
18 =x
18 stars
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:


I suggest using keep change flip