First of all, a bit of theory: since the area of a square is given by

where s is the length of the square. So, if we invert this function we have
.
Moreover, the diagonal of a square cuts the square in two isosceles right triangles, whose legs are the sides, so the diagonal is the hypothenuse and it can be found by

So, the diagonal is the side length, multiplied by the square root of 2.
With that being said, your function could be something like this:
double diagonalFromArea(double area) {
double side = Math.sqrt(area);
double diagonal = side * Math.sqrt(2);
return diagonal;
}
Answer:
$28.50
Step-by-step explanation:
21 chicken wings= $39.90
1 chicken wing= 39.90÷21= $1.90
15 chicken wings= 15×1.90= $28.50
Answer: 
Step-by-step explanation:
Given: The manager of a video game store found that 35 of the 140 people who preordered the latest baseball game canceled their orders the day before the game was released.
The probability that two customers who preorder the newest golf game will both cancel their orders the day before the game is released

Hence, The probability that two customers who preorder the newest golf game will both cancel their orders the day before the game is released is
.
10 = ax - 3b
First, add 3b to both sides. / Your problem should look like: 10 + 3b = ax.
Second, divide both sides by a. / Your problem should look like:

= x.
Third, switch sides. / Your problem should look like: x =

which is your answer.