Question

初二数学题：化简:2(√3-√2)+(1/√2+1)-(2/√3+1)

化简:2(√3-√2)+(1/√2+1)-(2/√3+1)急求急求急求！！！

Answer 1

2(√3-√2)+(1/√2+1)-(2/√3+1)
=2√3-2√2+√2/2+1-2√3/3-1
=4√3/3-3√2/2
不懂再问，望采纳，谢谢

Answer 2

1/1×2+1/2×3+1/3×4+……+1/19×20
=19/20
解：
1/(1*2)=1/1-1/2
1/(2*3)=1/2-1/3
1/(3*4)=1/3-1/4
:
:
1/(19*20)=1/19-1/20
所以原式=(1/1-1/2)+（1/2-1/3）+……+（1/19-1/20）=1-1/20=19/20