\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\)
\(\Leftrightarrow6x^2+27x+4x+18-\left(6x^2+x+12x+2\right)=x+1-x+6\)
\(\Leftrightarrow6x^2+27x+4x+18-6x^2-x-12x-2=7\)
\(\Leftrightarrow18x+16=7\)
\(\Leftrightarrow18x=-9\)
\(\Leftrightarrow\dfrac{-1}{2}\)
\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\)
\(\Leftrightarrow6x^2+27x+4x+18-6x^2-x-12x-2-x-1+x-6=0\)\(\Leftrightarrow18x-10=0\)
\(\Leftrightarrow18x=10\Rightarrow x=\dfrac{5}{9}\)
\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\)
\(\Rightarrow\left(6x^2+27x+4x+18\right)-\left(6x^2+x+12x+2\right)=x+1-x-6\)
\(\Rightarrow6x^2+27x+4x+18-6x^2-x-12x-2=1-6\)
\(\Rightarrow6x^2+27x+4x+18-6x^2-x-12x-2-1+6=0\)
\(\Rightarrow\left(6x^2-6x^2\right)+\left(27x+4x-x-12x\right)+\left(18-2-1+6\right)=0\)
\(\Rightarrow18x+21=0\Rightarrow18x=-21\)
\(\Rightarrow x=\dfrac{-7}{6}\)
Vậy \(x=\dfrac{-7}{6}\)
Chúc bạn học tốt!!!
\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\) (1)
\(\Leftrightarrow6x^2+27x+4x+18-\left(6x^2+x+12x+2\right)=x-1-x+6\)
\(\Leftrightarrow6x^2+27x+4x+18-\left(6x^2+13x+2\right)=7\)
\(\Leftrightarrow6x^2+27x+4x+18-6x^2-13x-2=7\)
\(\Leftrightarrow18x+16=7\)
\(\Leftrightarrow18x=7-16\)
\(\Leftrightarrow18x=-9\)
\(\Leftrightarrow x=-\dfrac{1}{2}\)
Vậy tập nghiệm phương trình (1) là \(S=\left\{-\dfrac{1}{2}\right\}\)
P/s: Trust me ;)
\(\left(3x+2\right)\left(2x+9\right)-\left(x+2\right)\left(6x+1\right)=\left(x+1\right)-\left(x-6\right)\\ \Leftrightarrow6x^2+31x+18-\left(6x^2+13x+2\right)-x-1+x-6=0\\ \Leftrightarrow28x+9=0\\ 28x=-9\\ x=-\dfrac{9}{28}\)
vậy......
