Question 119772
9*X+12(1-X)=10
9X+12-12X=10
-3X=10-12
-3X=-2
X=-2/-3
X=2/3 OR 40 MINUTES FOR THE 9 MPH SEGMENT.
1-2/3=1/3 OR 20 MINUTES FOR THE 12 MPH SEGMENT.
PROOF
9*2/3+12*1/3=10
6+4=10
10=10