1. \(x^2+3x+2=x^2+2x+x+2=x\left(x+2\right)+\left(x+2\right)=\left(x+2\right)\left(x+1\right)\) 2. \(3x^2+2x-1=3x^2+3x-x-1=3x\left(x+1\right)-\left(x+1\right)=\left(x+1\right)\left(3x-1\right)\)3 và 4 bạn xem lại đề nha mik giải ko đc 5. \(x^2+2x-8=x^2+4x-2x-8=x\left(x+4\right)-2\left(x+4\right)=\left(x+4\right)\left(x-2\right)\)