How do i factor this ?
Using complete sentences, explain how to completely factor 3x2 − 3x − 60.

Question

How do i factor this ? 
 Using complete sentences, explain how to completely factor 3x2 − 3x − 60.

pooja195 · Answer

to factor 3x2 − 3x − 60 you have to divide the whole equation by 3 because x^2 cannot be 3x^2
x^2-x-20 cannot be factored so you would have to use quadratic formula
-b+-√b^2-4ac
----------------
2
1+-√1^2-4(1)(-20)=1+-√1+80=1+-√81=9
1+9/2=5
or
1-9/2=-4
(x+5)(x-4)

anonymous · Answer

(x+4)(x-5) because if it were the other way it would end up x^2+x-20 not x^2-x-20

anonymous · Answer

The equation can be factored into 3(x-5)(x+4).  First, factor out the common factor 3, do not divide.  Since the remaining expression is $$x ^{2}-x-20$$  this represents a trinomial with leading coefficient of 1.  So, if it is going to factor, you need the factors of a -20 which add up to the coefficient of the middle term.  The coefficient of the middle term is a -1.  So the factors of -20 which add to a -1 are -5 and 4.  Therefore, your remaining polynomial factors as (x-5)(x+4).  And thus your entire expression, written in complete factored form is 3(x-5)(x+4).