20x=53-13
20x=40
20x/20=40/20
x=2
Answer:
og angle: 126.8
complementary angle: 53.2
og angle mirror (if any): 126.8
complementary angle mirror (if any): 53.2
Answer:
Step-by-step explanation:
Given expression:
To simplify the expression, we will use the formula (a - b)² = a² - 2ab + b².
[Where "a and b" are the first and second term in (a - b)²]
In this case, the first term of (2x - 12)² is "2x" and the second term is "12".
![\rightarrowtail (2x)^{2} - 2(2x)(12) + (12)^{2} \ \ \ \ \ \ \ \ \ \ \ \ \ \ [\small\text{First term = a = 2x; Second term = b = 12]}](https://tex.z-dn.net/?f=%5Crightarrowtail%20%282x%29%5E%7B2%7D%20-%202%282x%29%2812%29%20%2B%20%2812%29%5E%7B2%7D%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%5C%20%20%5B%5Csmall%5Ctext%7BFirst%20term%20%3D%20a%20%3D%202x%3B%20Second%20term%20%3D%20b%20%3D%2012%5D%7D)
Now, simplify the expression.
There are 2 short sides x and 1 long side y.
x+x+y=1,800
2x+y=1,800
y=1,800-2x
The area of the rectangle is A=x(1,800-x).
A is a function with variable x. Moreover it is a quadratic (second degree) function.
The graph of the function is a parabola which opens downwards, because the signs of the leading coefficients of the factors, multiply to minus:
(x)(-x)=-x^2.
This means that the highest point of the parabola, is its vertex V(h,k), so the function takes its largest value for x=h.
The roots of A=x(1,800-x) are x=0 and x=1,800, thus the x coordinate of the vertex, must be the midpoint of 0 and 1,800, that is 900.
Answer:
A=x(1,800-x)
largest area is when x=900
