81- answer is ok but im not suree
<span>Dawn was at 6 am.
Variables
a = distance from a to passing point
b = distance from b to passing point
c = speed of hiker 1
d = speed of hiker 2
x = number of hours prior to noon when dawn is
The first hiker travels for x hours to cover distance a, and the 2nd hiker then takes 9 hours to cover that same distance. This can be expressed as
a = cx = 9d
cx = 9d
x = 9d/c
The second hiker travels for x hours to cover distance b, and the 1st hiker then takes 4 hours to cover than same distance. Expressed as
b = dx = 4c
dx = 4c
x = 4c/d
We now have two expressions for x, set them equal to each other.
9d/c = 4c/d
Multiply both sides by d
9d^2/c = 4c
Divide both sides by c
9d^2/c^2 = 4
Interesting... Both sides are exact squares. Take the square root of both sides
3d/c = 2
d/c = 2/3
We now know the ratio of the speeds of the two hikers. Let's see what X is now.
x = 9d/c = 9*2/3 = 18/3 = 6
x = 4c/d = 4*3/2 = 12/2 = 6
Both expressions for x, claim x to be 6 hours. And 6 hours prior to noon is 6am.
We don't know the actual speeds of the two hikers, nor how far they actually walked. But we do know their relative speeds. And that's enough to figure out when dawn was.</span>
Answer:
-2
Step-by-step explanation:
4x:3=6:5.
4x/3=6/5
4x × 5=6×3
20 X=18
X=18-20
X=-2
Answer:
∠A = 30°
∠B = 60°
∠C= 90°
Step-by-step explanation:
This is a right triangle, you can see it mainly by the red square in C, and it is always used to mark 90 degrees.
Knowing that, you now know <em>∠C is 90°</em>
Now, to find ∠B, you should use the following equation:
This means that the sum of the three angles of a triangle gives 180. ALWAYS. So to find the missing angle, ∠B, do the following:
Fill the values of the equation with the angles you now know:
Solve the equation, passing the 30° and 90° to the other side of the equal sing with Inverse Operation:
<em>B = 60</em>
<em>Hope it helps!!</em>
