Answer:
D) 4
Explanation:
Roots of a polynomial must be factors of the last term.
In this case, the factors of 6 are +1, -1, +2, -2, +3, -3, +6, -6. The only factor that doesn't show up, given the options, is 4. This means that D is the correct answer.
There are 3 significant figures, if that answers the question.
It has 50kg with a velocity of 1 m/s times the speed of the cart divided by 2 and multiplied by kinectic x plus 5