二、填空 6.lim 3 解 lim 2x+3) lim x 2x+1 1+ 2x 2x3 3 32 1+ lim 2 X→00 =lim 1 1+2x) lim 00 8 二、填空 6． 2 3 lim 2 1 x x x →  x   +     + =_______ 解 2 3 lim 2 1 x x x → x   +     + 3 1 2 lim 1 1 2 x x x x →   +   =     +   3 1 2 lim 1 1 2 x x x x x →     +   =     +   2 3 3 2 3 2 1 1 2 2 2 3 lim 1 2 1 lim 1 2 x x x x x e e e x → →     +   = = =     +  