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The sum of the speeds of two trains is 721.5 miles per hour. If the speed of the first train is 8.5 mph faster than that of the second​ train, find the speeds of each.

Respuesta :

znk

Answer:

365.0 mi/h; 356.5 mi/h

Step-by-step explanation:

Let x = speed of first train

and y = speed of second train

We have two conditions:

(1) x + y = 721.5

(2) x = y + 8.5

Subtract y from each side of (2)     (3) x - y = 8.5

Add (1) and (3)                                          2x = 730.0

Divide each side by 2                          (4) x = 365.0

Substitute (4) into (1)                    365.0 + y = 721.5

Subtract 365.0 from each side                y = 356.5

The first train travels at 365.0 mi/h, and the second train travels

at 356.5 mi/h.

Check:

365.0 + 356.5 = 721.5     365.0 = 356.5 + 8.5

             721.5 = 721.5      365.0 = 365.0

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