SOLUTION: Here's my question: Pearly and Peggy Sue left their dorm room at the same time and headed in opposite directions. After 9 hours, they were 1,080 miles apart. If Pearly drove 20m

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Here's my question: Pearly and Peggy Sue left their dorm room at the same time and headed in opposite directions. After 9 hours, they were 1,080 miles apart. If Pearly drove 20m      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1036105: Here's my question:
Pearly and Peggy Sue left their dorm room at the same time and headed in opposite directions. After 9 hours, they were 1,080 miles apart. If Pearly drove 20mph faster than Peggy Sue, how fast did Peggy Sue drive?
I think the formula is +9x%2B%289x%2B20%29=1%2C080+ Is this right? If not, how do I do it?

Found 2 solutions by jorel555, MathTherapy:
Answer by jorel555(1290) About Me  (Show Source):
You can put this solution on YOUR website!
Let Peggy Sue's speed be n; then:
9n+9(n+20)=1080
9n+9n+180=1080
18n=900
n=50 mph
n+20=70 mph!!!!!!!!!!!!!!!

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Here's my question:
Pearly and Peggy Sue left their dorm room at the same time and headed in opposite directions. After 9 hours, they were 1,080 miles apart. If Pearly drove 20mph faster than Peggy Sue, how fast did Peggy Sue drive?
I think the formula is +9x%2B%289x%2B20%29=1%2C080+ Is this right? If not, how do I do it?
How did you get 9x? Isn't that the DISTANCE (times * speed) traveled by Peggy in 9 hours?
How did I get 9(x + 20)? Isn't that the DISTANCE (times * speed) traveled by Pearly in 9 hours?
When you add these 2 distances (Peggy's and Pearly's), what should they total? Shouldn't the 2 distances sum to the distance they are apart? Of course!!
Therefore, you should get: highlight_green%289x+%2B+9%28x+%2B+20%29+=+matrix%281%2C1%2C+%221%2C080%22%29%29, instead of 9x + (9x + 20) = 1