a: =>x:4/5=25/8*4/5=5/2
=>x=5/2*4/5=2
b: =>9/4x=10/8=5/4
=>x=5/4:9/4=5/9
c: =>(x+1/5)^2=9/25
=>x+1/5=3/5 hoặc x+1/5=-3/5
=>x=-4/5 hoặc x=2/5
e: =>x+1/2=0 hoặc 2/3-2x=0
=>x=-1/2 hoặc x=1/3
f: =>x(6+1/4-5-1/2)=1/4
=>x*3/4=1/4
=>x=1/3
h: =>|x-1/2|=3/4
=>x-1/2=3/4 hoặc x-1/2=-3/4
=>x=-1/4 hoặc x=5/4
