SOLUTION: 3. Steve traveled 600 miles at a certain speed. Had he gone 20mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.
y=time
xy=600
(x+20)(y-1)=600
Question 80653: 3. Steve traveled 600 miles at a certain speed. Had he gone 20mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.
y=time
xy=600
(x+20)(y-1)=600
Now what do I do? Found 2 solutions by ankor@dixie-net.com, josmiceli:Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! Steve traveled 600 miles at a certain speed. Had he gone 20mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.
y=time
xy=600
(x+20)(y-1)=600
Now what do I do?
:
I would do it this way:
:
Let x = original speed
Then (x+20) = faster speed (as you had)
:
Write a time equation: Time = dist/speed
:
Original time - 1 = Faster time - 1 =
:
Multiply equation by x(x+20) and you have:
600(x+20) - x(x+20) = 600x
:
600x + 12000 - x^2 - 20x = 600x
:
-x^2 - 20x + 600x - 600x + 12000 = 0
:
-x^2 - 20x + 12000 = 0
:
x^2 + 20x - 120000 = 0: multiplied equation by 0 (easier to factor)
:
Factors to:
(x+120)(x-100) = 0
:
x = +100, the positive solution is what we want here
:
Check:
600/100 - 1 = 600/120; proves our solution
You can put this solution on YOUR website! This is the way I do it
d = distance
s = speed
t = time
substitute
the common denominator is (reject the negative answer)
check the answer
OK
