Разложите на множители: X2*(X-5)-X*(X-5)-42*(X-5)

 X2*(X-5)-X*(X-5)-42*(X-5)=(x-5)(x^2-x-42)=(x-5)(x+6)(x-7)

 X2*(X-5)-X*(X-5)-42*(X-5)=(x-5)(x^2-x-42)=(x-5)(x+6)(x-7)