SOLUTION: Simone and Sean are running in a four-mile relay race. After Simone completes the first two miles, Sean runs the second two miles. Sean runs 1 mile per hour slower than Simone. Tog

Question 973854: Simone and Sean are running in a four-mile relay race. After Simone completes the first two miles, Sean runs the second two miles. Sean runs 1 mile per hour slower than Simone. Together they complete the race in 0.9 hours. How fast did each person run? Justify your answer.
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Simone and Sean are running in a four-mile relay race. After Simone completes the first two miles, Sean runs the second two miles. Sean runs 1 mile per hour slower than Simone. Together they complete the race in 0.9 hours. How fast did each person run?
***
let x= Sean's speed
x+1=simon's v speed
travel time=distance / speed

lcd: x(x+1)
2(x+1)+2x=0.9(x^2+x)
mult. by 10
20(x+1)+20x=9(x^2+x)
20x+20+20x=9x^2+9x
9x^2-31x-20=0
solve for x by quadratic formula:

a=9, b=-31, c=-20

How fast did each person run?
Sean: 4 mph
Simon: 5 mph

RELATED QUESTIONS
Simone has placed 18 dimes in a row on a table. Always starting from the left, first she... (answered by math-vortex)

Chas and Ben are running in a relay race. Chas runs at a rate of 15 feet per second for a (answered by Boreal)

sean walks 3/4 of a mile in 15 minutes.At the same pace,how far can sean walk in 1 hour... (answered by fractalier,josmiceli)

Two runners begin running laps around a one mile track at the same time. The first runner (answered by josmiceli)

you run a 10 mile race by running at a pace of 8 minutes per mile for 1 hour, and after... (answered by josgarithmetic)

Lary, Camille, and Simone are keeping track of how far they walk each day. At the end of... (answered by macston)

Sean biked the first half of a race in 30 minutes. He the biked the other half in 45... (answered by ankor@dixie-net.com)

Sean is buying a new DVD player and speakers for $315. The store offers him an... (answered by checkley77)

jack and jill are running in the 26-mile twin cities marathon. jack runs 6 miles per... (answered by palanisamy)