# Algebra(urgent)

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a boat moves through still wather at x kilometers(km) per hour. it travels 24km up stream against a current of 2km per hour and then returns with the current. The rate upstream is x-2 because the boat moves against the current and the rate downstream is x+2 because the boat moves with the current.

36.write an expression for the total time for the round trip.
28.use your answer to exercise 37 to find how long the round trip will take if the boat travels 10kilometers per hour through still water

• Algebra(urgent) -

time upstream = 24/(x-2)
time downstream = 24/(x+2)
total time = 24/(x-2) + 24/(x+2)

common denominator is (x+2)(x-2)

so total = (24(x+2) + 24(x-2))/((x+2)(x-2))
= 48x/(x^2 - 4)

Plug in x=10

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