Answer:
Step-by-step explanation:
Distance upstream = (34-c)(39/60) miles
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Distance downstream = (34+c)(29/60) miles
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Equation:
distance = rate*time
distance up = distance down
(34-c)(39/60) = (34+c)(29/60)
Multiply both sides by 60 to get:
39(34-c) = 29(34+c)
39*34 - 39c = 29*34 + 29c
68c = 340
c = 5 mph speed of the current
Multiply the first equation by 2
2x + 2y =30
now we’ll add the second equation to the first equation
2x + 2y =30
-2x+5y= -2
7y=28
divide by 7
y=4
now plug y back into the first equation
x + 4 = 15
subtract 4
x=11
If you apply the linear combination method to the system like:
<span>4(.25x + .5y = 3.75) → x + 2y = 15
(4x – 8y = 12) → x – 2y = 3
2x = 18
Then you can be sure that the solution of all this system is: (9,3). Hope this si what you were looking for</span>
1/7(1000) = 1/7(7000/7)
1*7000
7*7
7000
49
1000
7
so 1/7(1000) = 1000/7 or 142 6/7
