7 out of 12 have 31 im guessing
Answer: 6
Step-by-step explanation: DE is 4+2 so EF would be the same if it is equal.
Answer:

Step-by-step explanation:
From figure,

In triangle 

![\Rightarrow (a+b)^2=(a-b)^2+(O' D)^2\\\Rightarrow a^2+b^2+2ab-a^2-b^2+2ab=(O' D)^2\\\Rightarrow 4ab=(O' D)^2\\\Rightarrow O'D=2\sqrt{ab} \\\Rightarrow O' D=2\sqrt{ab}=AB \quad \quad [\because O' DAB\;\; \text{is a rectangle.}]](https://tex.z-dn.net/?f=%5CRightarrow%20%28a%2Bb%29%5E2%3D%28a-b%29%5E2%2B%28O%27%20D%29%5E2%5C%5C%5CRightarrow%20a%5E2%2Bb%5E2%2B2ab-a%5E2-b%5E2%2B2ab%3D%28O%27%20D%29%5E2%5C%5C%5CRightarrow%204ab%3D%28O%27%20D%29%5E2%5C%5C%5CRightarrow%20O%27D%3D2%5Csqrt%7Bab%7D%20%5C%5C%5CRightarrow%20O%27%20D%3D2%5Csqrt%7Bab%7D%3DAB%20%5Cquad%20%5Cquad%20%5B%5Cbecause%20O%27%20DAB%5C%3B%5C%3B%20%5Ctext%7Bis%20a%20rectangle.%7D%5D)
Hence, 
The answers are as follows:
x ≥ 15
y ≥ 6
x + y ≤ 30
10x + 8y ≥ 250
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Answer:
Option A. (-1, 0)
Step-by-step explanation:
In the figure attached,
Circle O is a unit circle (having radius r = 1 unit)
If a point A with central angles = θ, is lying on the circle then the coordinates of the point A will be,
x = r.cosθ
x = 1.cosθ = cosθ
and y = r.sinθ
y = 1.sinθ = sinθ
Therefore, coordinates representing the point A will be (cosθ, sinθ).
As per question the given point A is lying at P (a point having central angle θ = 180°)
Coordinates of point P will be
(x', y') → (cos180°, sin180°)
→ (-1, 0)
Therefore, Option A will be the answer.