Question

Cmr (3x-1)^2-(3x-2)^2=0

 

Answer 1

Theo đầu bài ta có:
\(\left(3x-1\right)^2-\left(3x-2\right)^2=0\)
\(\Rightarrow\left[\left(3x-1\right)+\left(3x-2\right)\right]\left[\left(3x-1\right)-\left(3x-2\right)\right]=0\)
\(\Rightarrow\left[\left(3x+3x\right)-\left(1+2\right)\right]\left[\left(3x-3x\right)-\left(1-2\right)\right]=0\)
\(\Rightarrow\left[6x-3\right]\cdot1=0\)
\(\Rightarrow3\left(2x-1\right)=0\)
\(\Rightarrow2x-1=0\)
\(\Rightarrow2x=1\)
\(\Rightarrow x=0,5\)