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bridgetolivares
Group Title
Explain, in complete sentences, how you would completely factor 20x2 – 28x – 48 by using the grouping method. How would you check your factors for accuracy?
 2 years ago
 2 years ago
bridgetolivares Group Title
Explain, in complete sentences, how you would completely factor 20x2 – 28x – 48 by using the grouping method. How would you check your factors for accuracy?
 2 years ago
 2 years ago

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bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
I don't wanna write an essay... I can solve, not explain..
 2 years ago

bridgetolivares Group TitleBest ResponseYou've already chosen the best response.0
that would be fine too.
 2 years ago

UnkleRhaukus Group TitleBest ResponseYou've already chosen the best response.0
i would start with factoring out the 4
 2 years ago

madscientist101 Group TitleBest ResponseYou've already chosen the best response.2
4(5x12)(x+1)
 2 years ago

madscientist101 Group TitleBest ResponseYou've already chosen the best response.2
you pull out the GCF first (which is 4), when you factor the trinomial. You can check you're answer by plugging in values for x... a nice value to use is like 1.
 2 years ago

bridgetolivares Group TitleBest ResponseYou've already chosen the best response.0
Thank you
 2 years ago

madscientist101 Group TitleBest ResponseYou've already chosen the best response.2
np :)
 2 years ago

mathg8 Group TitleBest ResponseYou've already chosen the best response.0
bahroom  being able to explain a concept demonstrates the mastery ...
 2 years ago

mathg8 Group TitleBest ResponseYou've already chosen the best response.0
bridget  I'm a math teacher. Can you explain how to factor 5x^2 7x 12 into (5x12)(x+1) ? hint : there is an almost exact method for factoring trinomials with leading coefficients different than 1 !
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
mathg, LE CHALLENGE ACCEPTED (One O in my name)
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
Explain, in complete sentences, how you would completely factor 20x2 – 28x – 48 by using the grouping method. Okay, group like terms, usually like terms are the ones that have factors or coefficients in common
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
Pull out a 4 from the whole thing: 4(5x^2  7x  6).. factor 5x^2  7x  6 further, i never learned that shortcut where factors of something add up to something, so I've always used this brute force method (discriminant :) ) D = b^24ac = (7)^2  4 * 5 * (6) = 49 + 120 = 169 x1 = (bsqrt(D))/(2a) = ((7)sqrt(169))/(2*5) = (7  13)/10 = 6/10 = 3/5 x2 = (b+sqrt(D))/(2a) = ((7)+sqrt(169))/(2*5) = (7 + 13)/10 = 20/10 = 2 Factors: (xx1)(xx2)
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
So your equation factored becomes: 4(x(3/5))(x2) or 4(x+(3/5))(x2)
 2 years ago

mathg8 Group TitleBest ResponseYou've already chosen the best response.0
Ok ... bahroom I have a different method ... faster , I think .
 2 years ago

mathg8 Group TitleBest ResponseYou've already chosen the best response.0
find the product of the leading coefficient and the free term (a*c), in our case (5)*(12)=60 , b the coefficient of x is the sum (7) . The task is to find two factors of (60) that add up to (7). After a bit of mental trial and error we can see the two factors we're looking for are 12 and 5 . Now rewrite the trinomial substituting 7x with 12x + 5x. 5x^2 +5x  12x 12  Factor by grouping : 5x(x+1)12(x+1) and factor again the GCF (x+1)(5x12) . QED
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
One O in my name
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
I thought math teachers paid attention to details
 2 years ago

mathg8 Group TitleBest ResponseYou've already chosen the best response.0
you made a mistake ... check your work ...
 2 years ago

mathg8 Group TitleBest ResponseYou've already chosen the best response.0
the 4(6) ≠ 48
 2 years ago

bahrom7893 Group TitleBest ResponseYou've already chosen the best response.4
yes i did, tnx for letting me know
 2 years ago
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