Answer:
E. 1,700 is your answer.
Step-by-step explanation:
What you do is you add 668 + 575 + 453 together.
668 + 575 + 453 = 1,696.
The hundreds place is the 9. Since the 9 is bigger than 4 it gets rounded up. That means the 6 in front of the 9 becomes a 7 and 9 and 6 become a zero.
E. 1,700 is your answer.
<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>
The answer is <span>2(–4y + 13) – 3y = –29
Step 1: Express </span><span>x from the second equation
Step 2: Substitute x into the first equation:
The system of equations is:
</span><span>2x – 3y = –29
x + 4y = 13
Step 1:
</span>The second equation is: x + 4y = 13
Rearrange it to get x: x = - 4y + 13
Step 2:
The first equation is: 2x – 3y = –29
The second equation is: x = - 4y + 13
Substitute x from the second equation into the first one:
2(-4y + 13) - 3y = -29
Therefore, the second choice is correct.