# SOLUTION: When Ace Airlines changed to planes that flew 100 km/h faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced by 30 min. Find the speed of the new pla

Algebra ->  Algebra  -> Percentage-and-ratio-word-problems -> SOLUTION: When Ace Airlines changed to planes that flew 100 km/h faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced by 30 min. Find the speed of the new pla      Log On

 Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations! Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!

 Word Problems: Problems on percentages, ratios, and fractions Solvers Lessons Answers archive Quiz In Depth

 Question 72139This question is from textbook Algebra and Trigonometry: Structure and Method : When Ace Airlines changed to planes that flew 100 km/h faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced by 30 min. Find the speed of the new plane.This question is from textbook Algebra and Trigonometry: Structure and Method Answer by checkley75(3666)   (Show Source): You can put this solution on YOUR website!2800/(X+100)+.5=2800/X (2800+.5X+50)/(X+100)=2800/X (2850+.5X)/(X+100)=2800/X NOW CROSS MULTIPLY (X+100)2800=X(2850+.5X) 2800X+280000=2850X+.5X^2 .5X^2+50X-280000=0 X^2+100X-560000=0 (X-700)(X+800)=0 X-700=0 X=700 ANSWER FOR THE SPEED OF THE SLOWER AIRPLANE X+100=800 IS THE SPEED OF THE FASTER PLANE. PROOF 2800/800+.5=2800/700 3.5+.5=4 4=4