Two cars leave Denver at the same time and travel in opposite directions.?
Two cars leave Denver at the same time and travel in opposite directions. One car travels 15 mph faster than the other car. The cars are 460 miles apart in 4 hours. How fast is each car traveling? please explain how to do this, dont just give me the answer!
Other - Cars & Transportation - 4 Answers
People's Answers, Critics, Comments, Opinions :
Answer 1 :
get a math tutor
Answer 2 :
T R D 4 x 460 4 x+15 460 8x+60=920 8x=860 x=107.5 x+15=122.5 t=time r=rate d= distance I think its an equals problem im not sure tho im 80% sure thats how u do it
Answer 3 :
The first car goes at speed X. The second car goes at speed X + 15. At 4 hour, the are 460 miles apart. So the first car goes 4 * (x) miles the second car goes 4 *(x + 15) miles add these together to get total miles (460 miles) So 4*(x) +4*(x+15) = 460 miles. Multiply that out. ***** 4*(x + 15) becomes 4x + (4 * 15) ***** 4*(x) becomes 4x 4x + 4x + (4 * 15) = 460 miles 4x + 4x + (60) = 460 miles. Subtact 60 from both sides. 4x + 4x = 400 miles combine 4x + 4x into 8x. So 8x = 400 miles. Divide both side by 8. X = 50 mile per hour. (first car) X + 15 = 65 mile per hour (second car) === Checks: first car: 50 MPH * 4 hours = 200 miles second car: 65 MPH * 4 hours = 260 miles. 200 miles + 260 miles = 460 miles. Done - good luck Hmmmm. I waited 1 hour and no response. Maybe I should just delete this answer...
Answer 4 :
You need to know the formula: distance = rate * time You are looking for the rate of the two cars. one car is going at x mph, and the other is going 15mph faster than the first, so x+15 mph. In 4 hours, the distance between the two cars is 460 miles. Now plug in what we know: distance = rate * time 460 miles = (rate of car 1 + rate of car 2) * 4 hours 460 miles = (x mph + (x+15) mph) * 4 hours 460 miles = (2x + 15) mph * 4 hours 460 miles = (2x + 15) miles/hour * 4 hours 460 miles = 4*(2x+15) miles*hour/hour 460 miles = 8x + 60 miles You can add/subtract/multiply/divide by the same amount to both sides of an equals equation, and maintain the equality. You want to get the variable you are solving for, in this case x, all by itself on one side of the equation, and only multiplied by 1. 460 miles = 8x + 60 miles 460 = 8x + 60 460 - 60 = 8x + 60 - 60 400 = 8x 400/8 = 8x/8 50 = x So, car one at x mph is going 50 mph, and car two at 15mph faster than car one is going 65 mph. You can check this by figuring out the distance that each car will have gone over the 4 hours at their speed, and then adding that distance together to see if it equals the 460 miles apart. distance of car one = rate of car one * time distance of car one = 50 mph * 4 hours distance of car one = 50*4 miles*hour/hour distance of car one = 200 miles distance of car two = rate of car two * time distance of car two = 65 mph * 4 hours distance of car two = 65*4 miles*hour/hour distance of car two = 260 miles Does the distance of car one plus the distance of car two, after 4 hours of travel, equal 460 miles? 460 miles ?= distance of car one + distance of car two 460 miles ?= 200 miles + 260 miles 460 miles = 460 miles Yea! our answers of 50mph and 65mph checks out!
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