Question

BT 1 TÌM X

A, \(\frac{3}{4}x+1=2\)

b, \(\frac{2}{3}+\frac{1}{3}:x=-1\)

c , |2x-1|=5

Answer 1

a) \(\frac{3}{4}x+1=2\)

\(\Leftrightarrow\)\(\frac{3}{4}x=1\)

\(\Leftrightarrow\)\(x=\frac{4}{3}\)

b) \(\frac{2}{3}+\frac{1}{3}:x=-1\)

\(\Leftrightarrow\)\(\frac{1}{3}:x=-\frac{5}{3}\)

\(\Leftrightarrow\)\(x=-\frac{1}{5}\)

c) \(\left|2x+1\right|=5\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}2x-1=5\\2x-1=-5\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}2x=6\\2x=-4\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=3\\x=-2\end{array}\right.\)

Answer 2

A/  \(\frac{3}{4}\)x+1=2 \(\Rightarrow\)\(\frac{3}{4}x=2-1\Rightarrow\frac{3}{4}x=1\Rightarrow x=1:\frac{3}{4}\Rightarrow x=\frac{4}{3}\)

Vậy x=...

B/  \(\frac{2}{3}\)+\(\frac{1}{3}\):x=−1 \(\Rightarrow\frac{1}{3}:x=-1-\frac{2}{3}\Rightarrow\frac{1}{3}:x=\frac{-5}{3}\Rightarrow x=\frac{1}{3}:\frac{-5}{3}\Rightarrow x=\frac{-1}{5}\)

Answer 3

C,  |2x-1|=5

\(\Rightarrow2x-1=5\) hoặc \(2x-1=-5\)

Ta Xét các TH

Th1: 2x-1=5 \(\Rightarrow2x=6\) \(\Rightarrow x=3\)

TH2 2x-1=-5 \(\Rightarrow2x=-4\Rightarrow x=-2\)

Vậy x=-2 hoặc x= 3

Answer 4