\(c,=8x\left(x-1\right)-10\left(x-1\right)=\left(x-1\right)\left(8x-10\right)=2\left(x-1\right)\left(4x-5\right)\\ d,x^2+2x-15=\left(x^2-3x\right)+\left(5x-15\right)=x\left(x-3\right)+5\left(x-3\right)=\left(x-3\right)\left(x+5\right)\\ k,x^2-5x+6=\left(x^2-2x\right)-\left(3x-6\right)=x\left(x-2\right)-3\left(x-2\right)=\left(x-2\right)\left(x-3\right)\\ n,x^2-6x-7=\left(x^2-7x\right)+\left(x-7\right)=x\left(x-7\right)+\left(x-7\right)=\left(x+1\right)\left(x-7\right)\)
\(s,x^5+x+1=\left(x^5-x^4+x^2\right)+\left(x^4-x^3+x\right)+\left(x^3-x^2+1\right)=x^2\left(x^3-x^2+1\right)+x\left(x^3-x^2+1\right)+\left(x^3-x^2+1\right)=\left(x^2+x+1\right)\left(x^3-x^2+1\right)\)
