Question

Tìm x biết: \(x+\frac{5}{2}x-\frac{3}{2}=2\frac{1}{4}\)

Answer 1

Đề bài : \(x+\frac{5}{2}x-\frac{3}{2}=2\frac{1}{4}\)

\(\Rightarrow x.\left(1+\frac{5}{2}\right)-\frac{3}{2}=\frac{9}{4}\)

\(\Rightarrow x.\frac{7}{2}=\frac{9}{4}+\frac{3}{2}\)

\(\Rightarrow x.\frac{7}{2}=\frac{15}{4}\)

\(\Rightarrow x=\frac{15}{4}:\frac{7}{2}\)

\(\Rightarrow x=\frac{15}{14}\)

Answer 2

\(x+\frac{5}{2}x-\frac{3}{2}=2\frac{1}{4}\)

=> \(x+\frac{5}{2}x=2\frac{1}{4}+\frac{3}{2}=\frac{15}{4}\)

=> \(\frac{7x}{2}=\frac{15}{4}\)

=> \(4\cdot7x=2\cdot15\)

=> \(28x=30\)

=> \(x=\frac{30}{28}=\frac{15}{14}\)