±11
Step-by-step explanation:
Even NO. roots are always contain ±.
Answer:
The answer is x = -3.
Step-by-step explanation:
The triangles ABC and EDF are congruent, meaning they have the same side lengths and angles measures.
The measure of DF, as both triangles are congruent, is equal to the measure of BC.
We can calculate the length of BC using the distance formula:
![\begin{gathered} D=\sqrt[]{(x_c-x_b)^2+(y_c-y_b_{})^2} \\ D=\sqrt[]{(2-2)^2+(-1-4)^2} \\ D=\sqrt[]{0^2+(-5)^2} \\ D=\sqrt[]{(-5)^2} \\ D=|-5| \\ D=5 \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20D%3D%5Csqrt%5B%5D%7B%28x_c-x_b%29%5E2%2B%28y_c-y_b_%7B%7D%29%5E2%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B%282-2%29%5E2%2B%28-1-4%29%5E2%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B0%5E2%2B%28-5%29%5E2%7D%20%5C%5C%20D%3D%5Csqrt%5B%5D%7B%28-5%29%5E2%7D%20%5C%5C%20D%3D%7C-5%7C%20%5C%5C%20D%3D5%20%5Cend%7Bgathered%7D)
As BC is congruent with DF and BC=5, the length of DF is 5 units.
A) x -y =1
B) x * y =1
B) y = 1/x
A) x -(1/x) = 1
Multiplying both sides by "x"
A) x^2 -1 = x
A) x^2 -x -1 = 0
Solving by the quadratic formula
x = 1.618 and
y = .618
Interestingly, the number 1.6180339... is called the "phi ratio" or the "golden ratio".
https://en.wikipedia.org/wiki/Golden_ratio