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3 years ago

5

The steamboat River Queen travels at the rate of 30km/h in still water. If it can travel 45 km up stream in the same amount of t

ime that it takes to go 63 km down stream what is the rate of the current.

1 answer:

const2013 [10]3 years ago

6 0

$x-the\ rate\ of\ the\ current\\t-time\\\\ \left\{\begin{array}{ccc}(30-x)t=45\\(30+x)t=63\end{array}\right\\ \left\{\begin{array}{ccc}t=\frac{45}{30-x}\\t=\frac{63}{30+x}\end{array}\right\\\\\frac{45}{30-x}=\frac{63}{30+x}\\\\cross\ multiply\\\\63(30-x)=45(30+x)\\1890-63x=1350+45x\\-63x-45x=1350-1890\\-108x=-540\ \ \ \ /:(-108)\\x=5\\\\Answer:The\ rate\ of\ the\ current\ is\ 5\ km/h.$

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lord [1]

Answer:

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3 years ago

Through: (-5, 5), perp. to y = 5/9x - 4

zysi [14]

Answer:

$y=-\frac{9}{5}x-4$

Step-by-step explanation:

<u><em>The complete question is:</em></u>

Find the equation of the line that passes through: (-5, 5), and is perpendicular to the line y = 5/9x - 4

step 1

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step 2

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substitute

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il63 [147K]

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3 years ago

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4 years ago