Suppose Xiao Ming's time is T 1, then

T 1=x/a+x/b=x(a+b)/ab

Let the time used by Xiao Wang be T2, the first half and the second half are T, ∴T2=2t, then

at+bt=2x

∴t(a+b)=2x,∴t=2x/(a+b)

∴T2=2t=4x/(a+b)

Use T 1-T2—

[x(a+b)/ab]-[4x/(a+b)]

=[x(a+b)？ -4abx]/ab(a+b)

=[(a？ +b？ +2ab-4ab)x]/[ab(a+b)]

=[(a-b)？ x]/[ab(a+b)]

∵ (a-b) & gt=0，x & gt0,∴[(a-b)？ x]>； =0

∫a and B are both > 0, ∴ [AB (A+B)] > 0

∴[(a-b)？ x]/[ab(a+b)]& gt； =0

∴t 1-t2>； =0

∴t 1>； =T2

To sum up, Xiao Ming spends more time than Xiao Wang, so Xiao Wang arrives at his destination first.

What should I do? ! Isn't it a little early to do this kind of topic for my friends in grade one? ! ! ! = Gu = ||| ... I don't know if you can understand a child's writing like this, ∫ = because, ∴ = so, > = means greater than or equal to orz. ..................

In short, it is best to understand. Copy if you don't understand. The correct rate can be guaranteed ~ feed you with bad children! = valley =

Don't waste my efforts to accept it > <