Answer: option D
Step-by-step explanation:
Remember the cosine identity:
Given the right triangle DFE shown in the image, you can identify that the adjacent side and the hypotenuse for the angle F of this triangle are:
Now you can substitute values into and then reduce the fraction.
THerefore you get:
Answer:
The width of the floor is 10 ft.
Step-by-step explanation:
First, you have to form expressions of width and length in terms of w. With the given information :
width = w ft
length = (w - 2) ft
Given that the area of rectange is A = length × width so you have to subtitute the expressions and value into the formula :
A = l × w
80 = (w - 2) × w
w(w - 2) = 80
w² - 2w = 80
w² - 2w - 80 = 0
(w + 8)(w - 10) = 0
w + 8 = 0
w = -8 (rejected)
w - 10 = 0
w = 10
Did they give values for the letters??
First, let me do the Mathematical part of that, and then I shall explain the theory behind it.
Mathematical part:
We are going to multiply 513 with 46. So the two partial products that we are going to choose are 40 and 6.
Multiply 513 with 6 first.
513
x46
--------------------------
18 (as 6*3 = 18)
60 (as 6*10 = 60; In 513, the digit at tenths place is 1, so 1*10=10)
3000 (as 6*500 = 3000; In 513, 5 is at hundredth place, so 5*100=500)
120 (as 40*3 = 120; since 4 is at the tenth place, so 4*10=40)
400 (as 40*10 = 400)
20000 (as 40*500 = 20000)
--------------------------
23598 (Add all of them)
Theory:
As you can see above that we have chosen the two partial products individually which are 6 and 40. Since 4 in 46 is in tenth place, we have to consider it 40 (since 4*10 = 40). One by one, we first multiply 6 with 513. Then we move to the tenth place, and multiply 513 with 40. At the end, we have added all the results we found after multiplication.
Check: If we check the multiplication result by using the calculator, we would get the same result (23598).
Another Method (instant):
513 * (40+6) = (513*40) + (513*6) = 23598.
Answer:
The answer is - 113 that is the correct answer skipping in three's and the first one is - 97
