Question

1,tìm x:

a,\(\dfrac{3}{4}-|2x+1|=\dfrac{7}{8}\)

b,\(2.|2x-3|=\dfrac{1}{2}\)

c,\(7,5-3.|5-2x|=-4,5\)

d,\(|x+\dfrac{4}{15}|-|-3,75|=-|-2,15|\)

giúp mình nha mọi người

Answer 1

a. \(\dfrac{3}{4}-\left|2x+1\right|=\dfrac{7}{8}\)

=> \(\left|2x+1\right|=\dfrac{3}{4}-\dfrac{7}{8}\)

=> \(\left|2x+1\right|=\dfrac{-1}{8}\)

=> \(\left\{{}\begin{matrix}2x+1=\dfrac{-1}{8}\\2x+1=\dfrac{1}{8}\end{matrix}\right.\) => \(\left\{{}\begin{matrix}x=\dfrac{-9}{16}\\x=\dfrac{-7}{16}\end{matrix}\right.\)

#Yiin

Answer 2

b. \(2.\left|2x-3\right|=\dfrac{1}{2}\)

=> \(\left|2x-3\right|=\dfrac{1}{4}\)

=> \(\left\{{}\begin{matrix}2x-3=\dfrac{1}{4}\\2x-3=\dfrac{-1}{4}\end{matrix}\right.\) => \(\left\{{}\begin{matrix}x=\dfrac{13}{8}\\x=\dfrac{11}{8}\end{matrix}\right.\)

Answer 3

c: =>3|2x-5|=7,5+4,5=12

=>|2x-5|=4

=>2x-5=4 hoặc 2x-5=-4

=>2x=9 hoặc 2x=1

=>x=9/2 hoặc x=1/2

d: =>|x+4/15|=-2,15+3,75=1,6

=>x+4/15=8/5 hoặc x+4/15=-8/5

=>x=4/3 hoặc x=-28/15