Bạn tham khảo cách làm!
`(3x+2)*(x+4)-(3x-1)*(x-5)=0`
\(\Leftrightarrow3x\left(x+4\right)+2\left(x+4\right)-3x\left(x-5\right)+1\left(x-5\right)=0\)
\(\Leftrightarrow3x^2+3x\cdot4+2x+2\cdot4-3x^2+3x\cdot5+x-5=0\)
\(\Leftrightarrow3x^2+12x+2x+8-3x^2+15x+x-5=0\)
\(\Leftrightarrow\left(3x^2-3x^2\right)+\left(12x+2x+15x+x\right)+\left(8-5\right)=0\)
\(\Leftrightarrow30x+3=0\)
\(\Leftrightarrow30x=0-3\)
`=> 30x=-3`
`-> x=-3 \div 30`
`-> x=-1/10 `
Đúng 1
Bình luận (0)