The LCD of 2/5 + k/4 = 9/10 is 20. Applying this LCD, we get:
8 + 5k = 18. Subtracting 8 from both sides: 5k = 10. Then k = 10/5, or k = 2.
I'm going to assume that the room is a rectangle.
The area of a rectangle is A = lw, where l=length of the rectangle and w=width of the rectangle.
You're given that the length, l = (x+5)ft and the width, w = (x+4)ft. You're also told that the area, A = 600 sq. ft. Plug these values into the equation for the area of a rectangle and FOIL to multiply the two factors:

Now subtract 600 from both sides to get a quadratic equation that's equal to zero. That way you can factor the quadratic to find the roots/solutions of your equation. One of the solutions is the value of x that you would use to find the dimensions of the room:

Now you know that x could be -29 or 20. For dimensions, the value of x must give you a positive value for length and width. That means x can only be 20. Plugging x=20 into your equations for the length and width, you get:
Length = x + 5 = 20 + 5 = 25 ft.
Width = x + 4 = 20 + 4 = 24 ft.
The dimensions of your room are 25ft (length) by 24ft (width).
Answer: $0.268
Step-by-step explanation: 5.36 divided by 20 = 0.268
Answer:

Step-by-step explanation:
sec(theta) is defined as: 
In the diagram you provided the hypotenuse of the triangle is sqrt(41) and the opposite side is 5, using these two sides, we can solve for the adjacent side by using the Pythagorean Theorem: 
So this gives us the equation where a=adjacent side:

Subtract 25 from both sides

Take the square root of both sides

So now plug this into the definition of sec(theta) and you get:
. This is in most simplified form since 41, has no factors besides 41 and 1.