Question

Tìm số hữu tỉ x: biết

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

b) 1/-5-2/3+một1/2.x=1/2

c) 2(1/4-3x)=1/5-4x

d) -5/2-3(1/3-x) =1/4-7x

Giúp t với.. Help me... Huhuhuhuhu 😣😣😣😣😣😣😣

Answer 1

a) \(-5x+\frac{1}{2}=\frac{2}{3}\\ -5x=\frac{2}{3}-\frac{1}{2}\\ -5x=\frac{1}{6}\\ x=\frac{1}{6}:\left(-5\right)\\ x=\frac{-1}{30}\)Vậy \(x=\frac{-1}{30}\)

b) \(\frac{1}{-5}-\frac{2}{3}+1\frac{1}{2}x=\frac{1}{2}\\ \frac{-13}{15}+\frac{3}{2}x=\frac{1}{2}\\ \frac{3}{2}x=\frac{1}{2}-\frac{-13}{15}\\ \frac{3}{2}x=\frac{41}{30}\\ x=\frac{41}{30}:\frac{3}{2}\\ x=\frac{41}{45}\)Vậy \(x=\frac{41}{45}\)

c) \(2\left(\frac{1}{4}-3x\right)=\frac{1}{5}-4x\\ \frac{1}{2}-6x=\frac{1}{5}-4x\\ \frac{1}{2}-\frac{1}{5}=6x-4x\\ \frac{3}{10}=2x\\ x=\frac{3}{10}:2\\ x=\frac{3}{20}\)Vậy \(x=\frac{3}{20}\)

d) \(\frac{-5}{2}-3\left(\frac{1}{3}-x\right)=\frac{1}{4}-7x\\ \frac{-5}{2}-1+3x=\frac{1}{4}-7x\\ \frac{-7}{2}+3x=\frac{1}{4}-7x\\ 7x+3x=\frac{1}{4}+\frac{7}{2}\\ 10x=\frac{15}{4}\\ x=\frac{15}{4}:10\\ x=\frac{3}{8}\)Vậy \(x=\frac{3}{8}\)

Answer 2

https://i.imgur.com/Mm8Vb1N.jpg

Answer 3

\(-5x+\frac{1}{2}=\frac{2}{3}\)

⇔\(\frac{-5x.6}{6}+\frac{3}{6}=\frac{4}{6}\)

➞\(30x+3=4\)

⇔\(30x=1\)

⇔\(x=\frac{1}{30}\)

Answer 4

a) \(-5x+\frac{1}{2}=\frac{2}{3}\)

=> \(-5x=\frac{2}{3}-\frac{1}{2}\)

=> \(-5x=\frac{1}{6}\)

=> \(x=\)\(\frac{1}{6}:\left(-5\right)\)

=> \(x=-\frac{1}{30}\)

Vậy \(x=-\frac{1}{30}\)

b) \(\frac{1}{-5}-\frac{2}{3}+1\frac{1}{2}.x=\frac{1}{2}\)

=> \(-\frac{1}{5}-\frac{2}{3}+\frac{3}{2}.x=\frac{1}{2}\)

=> \(\frac{19}{30}.x=\frac{1}{2}\)

=> \(x=\frac{1}{2}:\frac{19}{30}\)

=> \(x=\frac{15}{19}\)

Vậy \(x=\frac{15}{19}\)

c) 2 \(\left(\frac{1}{4}-3x\right)\) = \(\frac{1}{5}-4x\)

=> \(\frac{1}{2}-6x=\frac{1}{5}-4x\)

=> \(\frac{1}{2}-\frac{1}{5}=6x-4x\)

=> \(\frac{3}{10}=2x\)

=> \(x=\frac{3}{10}:2\)

=> \(x=\frac{3}{20}\)

Vậy \(x=\frac{3}{20}\)

Chúc bạn học tốt!