SOLUTION: john travelled 400 km from manipulate to a nearby proving. if in returning home he reduced his speed by 96m and able to reach manipulate 2 hours more time than going to the provin

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: john travelled 400 km from manipulate to a nearby proving. if in returning home he reduced his speed by 96m and able to reach manipulate 2 hours more time than going to the provin      Log On


   

Question 549686: john travelled 400 km from manipulate to a nearby proving. if in returning home he reduced his speed by 96m and able to reach manipulate 2 hours more time than going to the proving, what was his original speed?
Select a natural numbers between 1 to 50. square the digits and add. repeat this process until you see a pattern.
what other numbers end with one?
what happen if you do the process to number 37?
what conclusion can you give?

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let going speed be x mph
returning speed = x-96
d= 400
time difference = 2hours
400/(x-96) -400/x=2
LCD = x(x-96)
400x-400x+38400=2x^2-192x
2x^2-192x-38400=0
Find the roots of the equation by quadratic formula

a= 2 ,b= -192 ,c= -38400

b^2-4ac= 36864 - 307200
b^2-4ac= 344064
sqrt%28%09344064%09%29= 586.57
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=( 192 + 586.57 )/ 4
x1= 194.64
x2=( 192 -586.57 ) / 4
x2= -98.64
Ignore negative value
speed = 194.64 mph
m.ananth@hotmail.ca