Question

[Le Thanh Thai Son]

tìm x biết

1.  \(x\times\left(4.6+\frac{3}{5}\right)+7.2-8.15\)​
2. \(42+\frac{3}{7}\times\left[3\times-1\right]=12\) 
3. \(\left[2\times x-1\right]=\left[x+2\right]\) 
4. \(\frac{x+2}{5}=\frac{2-3\times x}{3}\) 

Answer 1

[nguyễn văn kiệt]

a) Thiếu đề (hoặc sai)

b) x đâu?

c)\(3x-1=x+2\)

\(\Rightarrow3x-x=2+1\)

\(\Rightarrow2x=3\)

\(\Rightarrow x=\frac{3}{2}\)

c) \(\frac{x+2}{5}=\frac{2-3x}{3}\)

\(\Rightarrow3.\left(x+2\right)=5.\left(2-3x\right)\)

\(\Rightarrow3x+6=10-15x\)

\(\Rightarrow3x+15x=10-6\)

\(\Rightarrow18x=4\)

\(\Rightarrow x=\frac{4}{18}=\frac{2}{9}\)

Answer 2

[Le Thanh Thai Son]

câu 1 là \(x\times\left(4.6+\frac{3}{5}\right)=7.2-8.15\)

câu 2 là \(42+\frac{3}{7}.\left[3\times x-1=12\right]\)