Question

分式 (29 22:5:35)先化简,后求值：(3-x)/(x-2)÷【x+2-5/(x-2)】,  其中x=2√2

Answer 1

(3-x)/(x-2)÷【x+2-5/(x-2)】= (3-x)/(x-2)÷【(x-3)*(x+3)/(x-2)】=(3-x)/(x-2)*(x-2)/[(x-3)*(x+3)]=-(x+3)=-(2√2 +3)=-(1+√2 )2

后面的2是平方