前一步与一楼一样
(x+2)/(x+3)=√3+√2+1
(x+2)/(x+3)-1=√3+√2+1-1
(x+2-x-3)/(x+3)=√3+√2
-1/(x+3)=√3+√2
第二步 (x-3/2x-4)/((5/x-2)-x-2)
=(x-3)/(2x-4)÷【5/(x-2)-{(x+2)(x-2)}/(x-2)】
=(x-3)(2x-4)÷(5-x的二次方+4)/(x-2)
=(x-3)/(2x-4)*(x-2)/(9-x的平方)
=-1/(6+6x)
把-1/(x+3)=√3+√2带入得(√3+√2)/2
取倒数
(x+2)/(x+3)=√3+√2+1
(x+2)/(x+3)-1=√3+√2+1-1
(x+2-x-3)/(x+3)=√3+√2
-1/(x+3)=√3+√2
原式=[(x-3)/2(x-2)]/[(5-x²+4)/(x-2)]
=[(x-3)/2(x-2)]/[-(x+3)(x-3)/(x-2)]
=-1/[2(x+3)]
=[-1/(x+3)]/2
=(√3+√2)/2