Select the correct choice below.
(a) 5 - 4x-12x^2=?
(b) The trinomial is not factorable.
Select the correct choice below.
(a) 5 - 4x-12x^2=?
(b) The trinomial is not factorable.
First re write the trinomial in descending order:
-12x^2-4x+5=0
Then factor out a -1:
-(12x^2+4x-5)=0
Write all possible factors for 12 and all possible factors of 5 to see all possibilities:
12: 5:
1 x 12. 1 x 5
2 x 6
3 x 4
remember that:
(ax + n)(bx + m)
amx and bnx must add up to our middle term which in this case is 4x.
the only possible combination that works is:
(2x - 1)(6x + 5)
so completely factored our answer is:
-(2x - 1)(6x + 5)
hope this helps