SOLUTION: Karen went on a 48 mile trip to a soccer game. On the way back, due to road construction she had to drive 24 miles per hour slower. This made the trip take 1 hour longer. How fast

Algebra.Com
Question 1150320: Karen went on a 48 mile trip to a soccer game. On the way back, due to road construction she had to drive 24 miles per hour slower. This made the trip take 1 hour longer. How fast did she drive to the soccer game?
Found 2 solutions by jim_thompson5910, MathTherapy:
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!

x = Karen's speed, in mph, going from her house to the soccer game
y = time it took, in hours, to go from Karen's house to the soccer game
d = 48 is the distance traveled in miles

When Karen goes from her house to the game, then we can set up this equation below:




Plug in d = 48, r = x, and t = y.



Divide both sides by x to isolate y.

We'll use this equation later

--------------------------------------------------

When heading back home, she takes 1 hour longer. So instead of driving for y hours, she drives for (y+1) hours. This is because her speed drops from x mph to (x-24) mph. The distance d is still the same at 48 miles.



Plug in r = (x-24) and t = (y+1)

Next, plug in y = 48/x, which was that equation we found earlier. At this point, we need to solve for x. But first let's do a bit of algebra to simplify this equation.



Use the distributive property

Use the distributive property again





Multiply both sides by x so that you clear out the fraction.

Note how the fraction is eliminated after using the distributive property.

Subtract 48x from both sides



--------------------------------------------------

In order to solve , we can use the quadratic formula.

Compare that equation to the general quadratic and we see that a = 1, b = -24, c = -1152.

Plug those a,b,c values into the quadratic formula below. Then simplify.

or

or

or

or

or

or

--------------------------------------------------

A negative speed does not make sense, so we ignore x = -24.
The only practical solution is x = 48.

So she drives from her house to the soccer game at 48 mph.
If x = 48, then y = 48/x = 48/48 = 1. This means it takes her 1 hour to drive from her house to the soccer game.

Also, if x = 48, then x-24 = 48-24 = 24 is her speed coming back home. The time it takes to drive back home is t = d/r = 48/24 = 2 hours, which fits with the description that she took one hour longer (compared to her journey from her house to the soccer game).

--------------------------------------------------

Answer: 48 miles per hour

Answer by MathTherapy(10557)   (Show Source): You can put this solution on YOUR website!
Karen went on a 48 mile trip to a soccer game. On the way back, due to road construction she had to drive 24 miles per hour slower. This made the trip take 1 hour longer. How fast did she drive to the soccer game?
EVERYTHING that the other person did is way too COMPLEX and WAY TOO time-consuming.
If I were you, I'd simply IGNORE it!
This is the correct way to do the problem:

Let the outgoing speed be S
Then the return speed = S - 24
The return trip took 1 hour longer, so we get the following TIME equation:
48(S - 24) = 48S - S(S - 24) ------ Multiplying by LCD, S(S - 24)



(S - 48)(S + 24) = 0
S, or OR S = - 24 (ignore)
That's IT!! No NOVEL has to be written on this!
RELATED QUESTIONS

Karen went on a 48 mile trip to a soccer game. On the way back, due to road construction... (answered by Alan3354,ikleyn)
Mikayla went on a 48 mile trip to a soccer game. On the way back, due to road... (answered by mananth)
Kristina went on a 260 mile trip to a soccer game. On the way back, due to road... (answered by stanbon,Theo)
Jenna went on a 90 mile trip to a soccer game. On the way back, due to road construction... (answered by josgarithmetic)
Mikayla went on a 60 mile trip to a soccer game. On the way back, due to road... (answered by mananth)
Hillary went on a 120 mile trip to a soccer game. On the way back, due to road... (answered by Alan3354)
Alejandra went on a 40 mile trip to a soccer game. On the way back, due to road... (answered by Fombitz)
Chloe went on a 168 mile trip to a soccer game. On the way back, due to road construction (answered by josmiceli)
Lauren went on a 102 mile trip to a soccer game. On the way back, due to road... (answered by josgarithmetic)