\(b,\dfrac{2\left(1-3x\right)}{5}-\dfrac{2+3x}{10}=7-\dfrac{3\left(2x+1\right)}{4}\)
\(\Rightarrow\dfrac{8\left(1-3x\right)}{20}-\dfrac{2\left(2+3x\right)}{20}=\dfrac{140}{20}-\dfrac{15\left(2x+1\right)}{20}\)
\(\Rightarrow\dfrac{8\left(1-3x\right)-2\left(2+3x\right)}{20}=\dfrac{140-15\left(2x+1\right)}{20}\)
\(\Rightarrow8\left(1-3x\right)-2\left(2+3x\right)=140-15\left(2x+1\right)\)
\(\Rightarrow8-24x-4-6x=140-30x-15\)
\(\Rightarrow4-30x=125-30x\)
\(\Rightarrow4=125\left(vô.lí\right)\)
Vậy pt vô nghiệm
Bài 6:
a: \(\Leftrightarrow\left(2x+1\right)\left(3x-2-5x+8\right)=0\)
=>(2x+1)(-2x+6)=0
=>x=-1/2 hoặc x=3
b: \(\Leftrightarrow\left(2x+1\right)\left(2x-1-3x+5\right)=0\)
=>(2x+1)(4-x)=0
=>x=-1/2 hoặc x=4
c: \(\Leftrightarrow\left(2x-2-x-1\right)\left(2x-2+x+1\right)=0\)
=>(x-3)(3x-1)=0
=>x=3 hoặc x=1/3
