Question

The sum of the speeds of two trains is 719.1 miles per hour. If the speed of the first train is 6.9 mph faster than that of the second​ train, find the speeds of each. What is the speed of the first​ train? nothing ▼ miles per hours ​(Type an integer or a​ decimal.) What is the speed of the second​ train? nothing ▼ hours miles per hour miles ​(Type an integer or a​ decimal.)

Answer 1

Answers

First train's speed is 363 mph

Second train's speed is 356.1 mph

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Explanation:

x = speed of first train, y = speed of second train

x+y = 719.1 because the two speeds add to this value (sum means result of addition)

x = y+6.9 due to the fact that the first train (x) is faster than the second train (y) by 6.9 mph

Use substitution to find that...

x+y = 719.1

y+6.9+y = 719.1 <--- replace x with y+6.9

2y+6.9 = 719.1

2y = 719.1-6.9 <--- subtract 6.9 from both sides

2y = 712.2

y = 712.2/2 <--- divide both sides by 2

y = 356.1

now use this y value to find x

x = y+6.9

x = 356.1+6.9

x = 363