Problema Solution
Justin drove to visit his parents who live 460 miles away. His way there his average speed was 9MPH Faster than on his way home. If he spent 23 hours driving, find the two rates.
Answer provided by our tutors
answer:
v2=36 MPH
v1=36+9= 45 MPH
solution:
let v1= speed towards
v2= speed going back
v1=9+v2
t=t1+t2
23=460/v1+460/v2
23=460/(9+v2)+460/v2
simplify:
23((v2)^2+9v2)=[460v2+460(9+v2)]
simplify further you will arevie this equation:
23(2)^2-713(v2)-4140=0
Solving quadratic equation:
v2=36 MPH
v1=36+9= 45 MPH