2160Equations

2160   Equations

题目描述

Given 2 equations on the variablesx andy , solve forx andy .

输入格式:

The first line of input contains N, the number of test cases. Each test case consists of two equations, each on a separate line. An empty line separates cases. An equation consists of two or more terms separated by addition, subtraction, or equality operators. A term is an integer, or a variable name (x or y) optionally preceded by a minus sign or an integer coefficient. There is exactly one equality operator. All operators are surrounded by spaces, and there are no spaces within terms.

输出格式:

For each case, print two lines, giving the values of x and y as rationals in simplest terms. If x or y has no unique rational value such that both equations hold, print "don't know" for its value. Print an empty line between cases.
输入样例 复制 
7
2x + 3y = x
5 = x + y + 3

2x + 3y = 0
10x = -15y

2x + 3y = 0
10x = -15y + 1

x = 1
3x = 6y

2x = 3x + -x + y
x + y = x + y

2x = -3
-2y = 3

1 = 2
x = 3
输出样例 复制 
3
-1

don't know
don't know

don't know
don't know

1
1/2

don't know
0

-3/2
-3/2

don't know
don't know

说明

1
1
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时空限制1000ms/128mb
题目来源
评测方式在线评测
题目类型
难        度