instead of such a long procedure .. there's a shortcut..
u know it takes x hours to travel A-B and return in twice as fast so u will cover return journey in half the time u spend while goin.. so x/2 ..add both x+x/2= 3x/2..
yes. this is the most intuitive way to solve it rather than get boggled down in formulas and pluggin in "smart numbers"
here is the "smart number" way
let d= 8 ("smart number")
going from A to B
plug in another smart number for x (x=4)
on the way back from B to A
4*?=8 (twice as fast)
therefore, 4+2=6 hours total
we originally set x=4
therefore, 6 = 3/2x