Answer:
width= 75 cm
Step-by-step explanation:
We need to recall the formula to calculate the area of a rectangle, since we are dealing with a rectangular window:
Area of rectangle = width * length
therefore, since they give us the window's area: 6525 
, and also the window's length: 87 cm, we just need to replace those values in the area formula and solve for the unknown "width". We do such by dividing both sides of the equation by 87 cm in order to isolate the unknown on one side of the equal sign;
The height of the smaller rectangle, let us say is 5
5 x 4 = 20
(multiply height of rectangle to scale factor)
the length is 4
4 x 4 = 16
(multiply length of rectangle to scale factor)
to find larger factor, divide smaller with larger
16/20 = 1/4
scale factor should be 1/4
multiply 20 with 4
perimeter of larger should be 80
hope this helps
Answer: y = -1, y = 6 (choice D)
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Work Shown:
y - (6/y) = 5
y*(y - (6/y)) = y*5 <<--- see note 1 below
y^2 - 6 = 5y
y^2 - 5y - 6 = 0
(y+1)(y-6) = 0 <<--- see note 2 below
y+1 = 0 or y-6 = 0
y = -1 or y = 6 which are the two answers
note 1: I multiplied both sides by y to clear out the fraction (the LCD is y)
note 2: I factored the left side by asking myself "what two numbers multiply to -6 and add to +5?" the answer to that question is +1 and -6 which helps lead to the factorization. An alternative route instead factoring is to use the quadratic formula
Answer:
A(2,3) -- over x-axis--> A(2,-3) --- over y=x --> A(-3,2)
same thing for the other points
in general
(x,y) ---> (x, -y) ---> (-y,x)
