Two trains leave the station at the same time, one heading east and the other west. The eastbound train travels at 85 miles per hour. The westbound train travels at 75 miles per hour. How long will it take for the two trains to be 192 miles apart?
Do not do any rounding.

It will take 1 hour and 12 minutes for the two trains to be 192 miles apart

Step-by-step explanation:

The total distance between the two trains is the distance traveled by both trains. The distance traveled by the eastbound train is 85 mph * elapsed time and the distance traveled by the westbound train is 75 * elapsed time.

The combined formula is distance traveled = speed of first train * elapsed time + speed of second train * elapsed time.

Since the elapsed time is equal for both trains then the formula is modified as distance traveled = (speed of first train + speed of second train) * elapsed time.

Solving for the elapsed time

distance traveled = (speed of first train + speed of second train) * elapsed time

192 miles = (85mph + 75 mph) * elapsed time

192 miles = 160 mph * elapsed time

elapsed time = 192 miles / 160 mph

elapsed time = 1.2 hours

elapsed time = 1 hour and 12 minutes

It will take 1 hour and 12 minutes for the two trains to be 192 miles apart.

the final amount you will pay is $68.04.

the tip is determined by the pre-tax amount, so we calculate the tip based on the original bill, not after we've added sales tax.

to find the tip:

we can divide 54.00 by 100 to get 1% of 54. then we multiply that by 18.

54 / 100 = .54

.54 x 18 = 9.72

tip = 9.72$

to find the tax:

we can divide 54.00 by 100 to get 1% of 54. then we can multiply that by 8 to get 8%.

54 / 100 = .54

.54 x 8 = 4.32

tax= 4.32

now we can add the tip and tax to the bill to get our total.

54 + 9.72 + 4.32 = 68.04

total: $68.04

step-by-step explanation:

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

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factorizing, we get that:

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then, the solutions are: or

nothing extraneous has been found!