We know that
<span>sec a = 5/4
</span>sec(a)=1/cos(a)
then
cos (a)=1/sec(a)
cos (a)=1/(5/4)=4/5---> is positive because the function cos is positive in IV quadrant
the answer is cos(a)=4/5
The 13-in. by 9-in. rectangle where the food listings fit has an area of 13 in. * 9 in. = 117 in.^2
Adding 48 in.^2 for the border, the total area of the menu with the border will be 117 in.^2 + 48 in.^2 = 165 in.^2
The border has to have uniform width around the menu. We need to find the width of the border. Let the border be x inches wide. Then since you have a border at each of the 4 sides, the border will add 2x to the length of the rectangle and 2x to the width of the rectangle. The menu will have a length of 2x + 13 and a width of 2x + 9. The area of the larger rectangle must by 165 in.^2. The area of a rectangle is length times width, so we get our equation:
(2x + 13)(2x + 9) = 165
Multiply out the left side (use FOIL or any other method you know):
4x^2 + 18x + 26x + 117 = 165
4x^2 + 44x + 117 = 165
4x^2 + 44x - 48 = 0
Divide both sides by 4.
x^2 + 11x - 12 = 0
Factor the left side.
(x + 12)(x - 1) = 0
x + 12 = 0 or x - 1 = 0
x = -12 or x = 1
The solution x = -12 is not valid for our problem because the width of a border cannot be a negative number. Discard the negative solution.
The solution is x = 1.
Answer: The border is 1 inch wide.
Check. Add 2 inches to the length and width of the food listings rectangle to get 15 inches by 11 inches. A = 15 in. * 11 in.= 165 in.^2. Now subtract the area of the border, 48 in.^2, 165 in.^2 = 48 in.^2 = 117 in.^2, and you get the area of the 13-in. by 9-in. rectangle. This shows that our solution is correct.
Answer:
5/2 x^2y^2
Step-by-step explanation:
( x^2 - 3/5y^2)^2 + (3/4 x^2 + 4/5 y^2)^2 - (5/4x^2 - y^2)^2
= x^4 - 6/5x^2y^2 + 9/25y^4 + 9/16x^4 + 6/5x^2y^2 + 16/25y^4 - ( 25/16x^4
- 5/2x^2y^2 + y^4)
Distributing the negative over the parentheses:-
= x^4 - 6/5x^2y^2 + 9/25y^4 + 9/16x^4 + 6/5x^2y^2 + 16/25y^4
- 25/16x^4
+ 5/2x^2y^2 - y^4
Bringing like terms together
x^4 + 9/16x^4 - 25/16x^4 - 6/5x^2y^2 + 6/5x^2y^2 + 5/2x^2y^2 + 16/25y^4 + 9/25y^4
- y^4
Adding like terms:-
= 5/2 x^2y^2 Answer
Answer:
(2, 22 )
Step-by-step explanation:
Given the 2 equations
y = 7x + 8 → (1)
y = x + 20 → (2)
Substitute y = 7x + 8 into (2)
7x + 8 = x + 20 ( subtract x from both sides )
6x + 8 = 20 ( subtract 8 from both sides )
6x = 12 ( divide both sides by 6 )
x = 2
Substitute x = 2 in (2) for corresponding value of y
y = x + 20 = 2 + 20 = 22
Solution is (2, 22 )
I pretty sure that the answer would be 6 50/117 but if you get a fraction calculator app it can help more.
