Answer:
r = (ab)/(a+b)
Step-by-step explanation:
Consider the attached sketch. The diagram shows base b at the bottom and base a at the top. The height of the trapezoid must be twice the radius. The point where the slant side of the trapezoid is tangent to the inscribed circle divides that slant side into two parts: lengths (a-r) and (b-r). The sum of these lengths is the length of the slant side, which is the hypotenuse of a right triangle with one leg equal to 2r and the other leg equal to (b-a).
Using the Pythagorean theorem, we can write the relation ...
((a-r) +(b-r))^2 = (2r)^2 +(b -a)^2
a^2 +2ab +b^2 -4r(a+b) +4r^2 = 4r^2 +b^2 -2ab +a^2
-4r(a+b) = -4ab . . . . . . . . subtract common terms from both sides, also -2ab
r = ab/(a+b) . . . . . . . . . divide by the coefficient of r
The radius of the inscribed circle in a right trapezoid is r = ab/(a+b).
_____
The graph in the second attachment shows a trapezoid with the radius calculated as above.
c. C = 0.41(w - 5) + 10.8
(w - 5) will represent the number of pounds over 5. For example, for a weight of 6 pounds, 6-5 = 1 is the number of pounds over 5.
The cost is $0.41 for each pound over 5, so that cost can be represented by ...
... 0.41(w - 5)
This charge is in addition to the base charge of $10.80, so the total cost will be ...
... C = 0.41(w - 5) + 10.80
O A. 4,/25
B. 2V50
O C. 5,2
O D. 10
SUBMIT
Answer:
D.10
Hope you could get an idea from here.
Doubt clarification - use comment section.
The solution is x = 9 and y = 4, meaning Brody would work 9 hours babysitting and 4 hours cleaning tables to satisfy both conditions (total hours ≤ 13 and total earnings ≥ $150).
Given:
Brody can work a maximum of 13 hours: x + y ≤ 13
Brody must earn at least $150: 10x + 15y ≥ 150
These are the two inequalities we need to solve graphically.
Graph the first inequality: x + y ≤ 13
This inequality represents the total number of hours Brody can work, which cannot exceed 13 hours. We'll plot the line x + y = 13 and shade the region below it.
Graph the second inequality: 10x + 15y ≥ 150
This inequality represents the total earnings Brody needs to make, which should be at least $150. Let's simplify it to 2x + 3y ≥ 30. We'll plot the line 2x + 3y = 30 and shade the region above it.
Now, let's find the point where the shaded regions of both inequalities overlap. This point will represent the feasible solution where Brody's working hours and earnings satisfy both conditions.
Solving the system of inequalities graphically, you will find the point of intersection. However, since I can't create a graphical representation here, I'll explain how to calculate the solution point algebraically:
First, solve the equation x + y = 13 for y:
y = 13 - x
Now substitute this value of y into the equation 2x + 3y = 30:
2x + 3(13 - x) = 30
2x + 39 - 3x = 30
-x = -9
x = 9
Now substitute the value of x back into the equation y = 13 - x:
y = 13 - 9
y = 4
So, the solution is x = 9 and y = 4, meaning Brody would work 9 hours babysitting and 4 hours cleaning tables to satisfy both conditions (total hours ≤ 13 and total earnings ≥ $150).
To know more about inequalities:
#SPJ3
Graph y≤13−x (shading down)
graph y≥10− 3/2x (shading up)
Answer:
1).
7, rational
2).
2.36 (repeating), irrational
3).
4).