Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
EmmaH
Group Title
Factor the trinomial: 4x^2  8x  5
(2x + 1)(2x  5)
(4x + 1)(x  5)
(4x  5)(x + 1)
prime
 one year ago
 one year ago
EmmaH Group Title
Factor the trinomial: 4x^2  8x  5 (2x + 1)(2x  5) (4x + 1)(x  5) (4x  5)(x + 1) prime
 one year ago
 one year ago

This Question is Closed

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
how do i solve this?
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
trying to pick from a multiple choice is simpler than trying to work thru the math. I always separate taking multiple choice from actually doing math.
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
we can deduce the the FL parts of foil are the same for every given option. if we can reduce this to the proper OI part that would reduce the work load
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
im not trying to find the answer im trying to understand it
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
i know that the first thing i have to do it multiply the first and last number right?
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
which would be 20
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
now multiply the "inside" numbers
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
um i thought i was suppose to find the factors of 20 then use that factors that add to 8?
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
im not sure if we are seeing the same thing at the moment. take the forms: (a+b)(c+d) if ac equals the first term; and bd equals the last term; then we need to determine the middle term by: ac+bd
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
i know its not this one, but to example my idea ... (4x  5)(x + 1) 4x*x = 4x^2 5*1 = 5 and our given setup is 4x^2 8x 5 all the options give us the same first and last terms so we need to determine a suitable "middle" setup
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
im pretty sure im not doing foil im ffactoring the trinomial
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
(4x  5)(x + 1) 4x * 1 = 4x 5 * x = 5x 4x  5x is not equal to 8x so we can rule that out
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
ok so its 10,2?
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
factoring produces a foil; and foil results in the equation they want factored 10,2 is perfect for us
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
so id write it like thsi? 4x^2+2x10x5?
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
that looks suitable to me; i was never really good at the factor by grouping stuff :)
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
so then what do i do thats no9t one of te answers?
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
then you group it, and factor our the groups, then factor again ... which is why i never really go that route in these ... (4x^2+2x)+(10x5) 2x(2x+1)5(2x+1) (2x+1)(2x5)
 one year ago

rosedewittbukater Group TitleBest ResponseYou've already chosen the best response.1
I responded to your other question of this.
 one year ago

rosedewittbukater Group TitleBest ResponseYou've already chosen the best response.1
4x^2  8x  5 Ok so I'll try to explain this the way I understand it. Usually to factor you have to find 2 numbers that multiply to equal the last number, and add up to equal the number part of the middle. I'll just use \[ax ^{2}+bx+c\] as an example equation. So you have to find 2 numbers that multiply to get c, and add up to get b. Then you would usually take those 2 numbers and use it to factor and get (x+?)(x+?). But since there is a number for a that is not 1 in your equation, it's a little different. First, multiply the first and last numbers 4 and 5 (a and c in the example equation). You get 20. So try to find 2 number that are factors of 20 and add up to equal 8. Just start to list the factors off on paper or in your head. Remember to include the negatives. 1, 20 1, 20 2, 10 2, 10 These add up to equal 8 Then put 2 and 10 to separate the middle part of the equation. \[4x ^{2}+2x10x5\]Then group the equation into 2 separate parts. \[(4x ^{2}+2x)+(10x5)\]Then you take out any common factors from the parentheses.\[2x(2x+1)5(2x+1)\]And then group together the parts you took out, which are the 2x and 5. same.\[(2x5)(2x+1)\]It becomes this because 2x+1 are the There's your answer. Hope this helps!
 one year ago

EmmaH Group TitleBest ResponseYou've already chosen the best response.0
thank you all soooooooooo much!!!!
 one year ago

amistre64 Group TitleBest ResponseYou've already chosen the best response.1
rose has a pretty detailed answer; not alot of interaction allowed in it, but a pretty detailed answer nonetheless :)
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.