#include<bits/stdc++.h> using namespace std; int T; int a,b,c,d; int main(){ cin>>T; getchar(); while(T--){ scanf("%d",&a); getchar(); if(getchar()=='-'){ scanf("%d",&b); b*=-1; } else scanf("%d",&b); getchar(); scanf("%d",&c); getchar(); if(getchar()=='-'){ scanf("%d",&d); d*=-1; }else scanf("%d",&d); printf("%0.5f\n",(d-b)*1.0/(a-c)); } }