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 3 years ago
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?
 3 years ago
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?

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

bridgetolivares
 3 years ago
Best ResponseYou've already chosen the best response.0that would be fine too.

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

madscientist101
 3 years ago
Best ResponseYou've already chosen the best response.2you 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.

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

mathg8
 3 years ago
Best ResponseYou've already chosen the best response.0bridget  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 !

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

bahrom7893
 3 years ago
Best ResponseYou've already chosen the best response.4Explain, 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

bahrom7893
 3 years ago
Best ResponseYou've already chosen the best response.4Pull 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)

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

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

mathg8
 3 years ago
Best ResponseYou've already chosen the best response.0find 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

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

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

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