Since you have the answers given, just track their walking.
After one hour, one guy has covered 3mi and the other 4mi, which is in total 7, not 14
After 2 hours, one guy has covered 6mi and the other 8mi, which is 14mi
The algebraic way would be:
3x +4x = 14 *x being the hour
7x = 14
x =2
Answer:

Step-by-step explanation:
We have to calculate the time derivative of T=PV/nR with P and V variable and n and R constants. This is:

What we have to do is the derivative of a product:

Substituting, we have:

where all these values are given since the time derivatives of P and V are their variation rate, using minutes.
We then substitute everything, noticing that already everything is in the same system of units so they cancel out:

And then just calculate:

5/9 = .55555555555 yards traveled per hop
15/9 = 1.6666667 feet per hop
To solve this system of equations, since y is already isolated in both equations, you can set the expressions to equal each other to solve for x:
-x + 2 = - 5x - 6
-x + 5x = -6 - 2
4x = -8
x = -2
Now that we have x, we can substitute it into one of the equations to find y:
y = -(-2) + 2
y = 2 + 2
y = 4
The last step is to substitute both values into both equations to see if they are correct:
4 = -(-2) + 2 --> 4 = 2 + 2 <--True
4 = -5(-2) - 6 --> 4 = 10 - 6 <--True
Answer:
x = -2
y = 4
The sampling technique used when A scientist chooses twenty people at random from each class is stratified sampling.
<h3>What is
stratified sampling?</h3>
Stratified sampling can be described as the type of sampling method whereby the total population is been divided into smaller groups or strata.
This usually done to complete the sampling process, hence The sampling technique used when A scientist chooses twenty people at random from each class is stratified sampling.
Read more on the stratified sampling here:
brainly.com/question/1954758
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