Cho bt M = (1/ √x-1+ √x/x-1).x- √x/2 √x+1 vs x 0 $\geq$ ; x $\neq$ 1 1. rút gọn M 2. tìm x để M =1/3 01/07/2021 Bởi Alexandra Cho bt M = (1/ √x-1+ √x/x-1).x- √x/2 √x+1 vs x 0 $\geq$ ; x $\neq$ 1 1. rút gọn M 2. tìm x để M =1/3
C1 : M=(√x+1+√x/(√x-1)(√x+1).√x(√x-1)/(2√x+1) =(2√x+1).√x(√x-1)/(√x-1)(√x+1)(2√x+1) =√x/√x+1 C2 : M=1/3<=>√x/√x+1=3√x=√x+1=> 2√x=1=>√x=1/2 =>1/4(TMĐKXĐ) Vậy M=1/3<=>x=1/4 Bình luận
C1 : M=(√x+1+√x/(√x-1)(√x+1).√x(√x-1)/(2√x+1)
=(2√x+1).√x(√x-1)/(√x-1)(√x+1)(2√x+1)
=√x/√x+1
C2 : M=1/3<=>√x/√x+1=3√x=√x+1=> 2√x=1=>√x=1/2
=>1/4(TMĐKXĐ)
Vậy M=1/3<=>x=1/4