SOLUTION: Factor Each Trinomial : -4x^2+11x+20 I'm confused on this one, help me please show all work! Thanks.

Question 853839: Factor Each Trinomial : -4x^2+11x+20
I'm confused on this one, help me please show all work! Thanks.
Found 2 solutions by rothauserc, LinnW:
Answer by rothauserc(4718) (Show Source): You can put this solution on YOUR website!
we are given -4x^2+11x+20 to factor
first write down all factors of 20
5,2,2,20,1
try the following
4x +5
-x +4
we see that we get -4x^2+11x+20
therefore
(4x+5)(-x+4) are factors of -4x^2+11x+20

Answer by LinnW(1048) (Show Source): You can put this solution on YOUR website!
-4x^2+11x+20
A good way is to start by factoring out -1
-1(4x^2-11x-20)
Now factor by grouping 4x^2-11x-20
We want two numbers multiplied to get (4)(-20) = -80
where the two numbers added give us -11
Possible factors
1,80
2,40
4,20
5,16 This is the pair we want since 16-5 = 11
The actual pair will be 5,-16
4x^2 -16x +5x -20
4x(x - 4) +5(x - 4)
(4x + 5)(x - 4)
Now put the -1 back in
(-1)(4x + 5)(x - 4)

RELATED QUESTIONS
Hi help me please show all work! Solve Each Trinomial Thank you!... (answered by jim_thompson5910,josmiceli)
please help me solve by factoring. 4x^2-11x+6=0 and show work so i can do this on (answered by jim_thompson5910)
Could Someone please help, and show me step by step if possible so that I can complete... (answered by edjones)
Please help me factor this trinomial:... (answered by ewatrrr)
Hello, I am a student who is in Grade 11 and in Mathematics Grade 11 Foundations. We... (answered by mouk)
I am having to multiply the fractions, please show me how to do this. 2x^2-x-3... (answered by Earlsdon,jim_thompson5910)
I have to factor each trinomial 3x^3 y^2 - 3x^2y^2 + 3xy^2 Can someone please help... (answered by drj,Zsurvivalist)
Hi, could you please help me solve this question, thanks. Factor each trinomial: (answered by jim_thompson5910,mouk)
1. Graph the given function and show your work: f(x)=-2x-5 I'm confused on this one,... (answered by stanbon)