5/(x+1)+4/(y-2)=27/(x+1)+3/(2-y)=13/207/(x+1)-3/(y-2)=13/20令a=1/(x+1),b=1/(y-2)5a+4b=2 (1)7a-3b=13/20 (2)(1)*3+(2)*415a+28a=6+13/5=8.643a=8.6a=1/5b=(2-5a)/4=1/4所以x+1=1/a=5y-2=1/b=4x=4y=6
