(a^2+2ab+b^2)/(a^2 - b^2)=(a+b)²/[(a+b)(a-b)]=(a+b)/(a-b)当a=根号3 +1 b=根号3 -1时原式=（√3+1+√3-1）/（√3+1-√3+1）=2√3÷2=√3
原式=(a+b)²/(a+b)9a-b)=(a+b)/(a-b)=(√3+1+√3-1)/(√3+1-√3+1)=2√3/2=√3
