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.)

Answers

First train's speed is 363 mph

Second train's speed is 356.1 mph

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

step-by-step explanation:

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.