Answer: 8 (The second option).
Step-by-step explanation:
1. To solve this exercise you draw a line to a point O, this lines will bisect the angle of Z∠60°. Then will obtain two into two right triangles with two angles of 30° at the point Z.
2. The lenght XY will be twice the lengt XO or YO.
3. Let's calclate XO as following:

4. Then, XY is:

Answer:
Therefore the rate change of distance between the car and the person at the instant, the car is 24 m from the intersection is 12 m/s.
Step-by-step explanation:
Given that,
A person stand 10 meters east of an intersection and watches a car driving towards the intersection from the north at 13 m/s.
From Pythagorean Theorem,
(The distance between car and person)²= (The distance of the car from intersection)²+ (The distance of the person from intersection)²+
Assume that the distance of the car from the intersection and from the person be x and y at any time t respectively.
∴y²= x²+10²

Differentiating with respect to t


Since the car driving towards the intersection at 13 m/s.
so,

Now



= -12 m/s
Negative sign denotes the distance between the car and the person decrease.
Therefore the rate change of distance between the car and the person at the instant, the car is 24 m from the intersection is 12 m/s.
Answer is B. No matter what the x or y will be the result will be 0. Anything multiplied by 0 is equal to 0.
Here: (Aₓ, Ay) = (-3,-4), (Bₓ, By) = (-7,0), (Cₓ, Cy) = (-3, 4)
Now, Formula of area of triangle is:
area = [Aₓ(By - Cy) + Bₓ(Cy - Ay) + Cₓ(Ay - By)] / 2
Substitute the values in to the expression,
area = [-3(0-4) - 7(-4-(-4)) - 3(-4-0)] / 2
area = [-3(-4) -7(0) -3(-4)] / 2
area = [12-0+12] / 2
area = 24 / 2
area = 12
Final answer would be 12 units.
Hope this helps!
If i'm not wrong its distributing property of addition. <span />