Okay so I think I did this wrong (like I read the question wrong) but I think the lowest number of times you would have to swap the cards is 9. Like I said, not sure, so if you have the real answer please tell me because now I'm curious...
but I hope this helps somewhat!
If the speed of the stream is x
Time is given by d/r , where r is the rate and d is the distance;
Rate for upstream = (15-x) mph and that of down stream is (15 +x) mph
The time taken will be the same;
Thus; 2/(15-x) = 4/(15+x)
cross multiplying;
30 +2x = 60 -4x
6x = 30
x =5
Therefore the rate of the river is 5 mph
Answer:
x=-1
Step-by-step explanation:
Answer:
Division property
Step-by-step explanation:
The property which states that we can divide both side of the equation by the same non-zero number is called the division property of equality.
The goal of dividing an equation is to isolate the unknown variable on one side.
For example, let the equation be:
2×x=10
Since the unknown variable x is being multiplied by the number 2, to isolate the variable an inverse operation needs to be applied - division:
2×x<u>÷2</u>=10<u>÷2</u>
<u />
Careful! Never forget to write the same operation on both sides of the equation! When doing so, the solution of the equation stays the same, i.e. we get an equivalent equation.
Your answer would be 4x-6y-12
