Answer:
Step-by-step explanation:
Given;
x² - 2x - 1 = 0
Solve by completing the square method;
⇒ take the constant to the right hand side of the equation.
x² - 2x = 1
⇒ take half of coefficient of x = ¹/₂ x -2 = -1
⇒ square half of coefficient of x and add it to the both sides of the equation
⇒ take the square root of both sides;
Therefore, option B is the right solution.
The perimeter is:
P = 2x + 2y = 80
The area is:
A = x * y
The area as a function of a variable is:
A (x) = x * (40-x)
Rewriting we have:
A (x) = 40x-x ^ 2
We derive the function:
A '(x) = 40-2x
We equal zero and clear x:
40-2x = 0
2x = 40
x = 40/2
x = 20 feet
The other dimension is:
y = 40 - x
y = 40 - 20
y = 20 feet
The area will be:
A = x * y
A = 20 * 20
A = 400 feet ^ 2
Answer:
The dimensions are:
x = 20 feet
y = 20 feet
The area is:
A = 400 feet ^ 2
Answer:
C. 61
Step-by-step explanation:
Two sides are equal, so the triangle is an isosceles triangle.
Both base angles are equal.
Angles in a triangle add up to 180 degrees.
58 + x + x = 180
58 + 2x = 180
2x = 122
x = 61
The answer is c because all you are doing here is subbing the variable r for 5b.
