Question

[Nguyen Dang Hai Dang]

Tìm x:

a) 3/4x + 2/5x=1

b) ( x-9/11)( x-25/31)=0

c) x-3/7:9/14=7/3

Ai giúp đc k ah?!

Answer 1

[Thu Phương]

a,x.(3\4+2\5)=1

x.20\23=1

x=1:20\23

x=20\23

b,x-9\11=0 hoặc x-25\31=0

x=9\11                x=25\31

c,x-3\7.9\14=7\3

x-2\3=7\3

x=7\3+2\3

x=9\3

x=3