\(=x^2+x+6x+6\\ =x\left(x+1\right)+6\left(x+1\right)\\ =\left(x+6\right)\left(x+1\right)\)
\(c,x^2+7x+6=x^2+x+6x+6=\left(x^2+x\right)+\left(6x+6\right)=x.\left(x+1\right)+6.\left(x+1\right)=\left(x+1\right).\left(x+6\right)\)
`=> x ^2 + x + 6 x + 6`
`=>x ( x + 1 ) + 6 ( x + 1 )`
`=> ( x + 6 ) ( x + 1 )`