how to factor these problems- math help?
please help factor these problems and show work!!!
- Dr. J.Lv 69 years agoFavorite Answer
2. r (r^2-2r-12)=
- 9 years ago
1.) 2c^2-242 = 2(c^2-121) = 2(c+11)(c-11)
2.) r^3-2r^2-12r = r(r^2-2r-12)
To factor further, we want to factor r^2-2r-12. Use the quadratic formula to find the zeros.
The zeros are 2+sqrt(13) and 2-sqrt(13). Therefore, the factors are (r-(2+sqrt(13))) and (r-(2-sqrt(13)))
so the complete factorization is r(r-(2+sqrt(13)))(r-(2-sqrt(13))) - there won't be so many parentheses when you simplify and write out the sort using the normal symbol.
Hope this helps! :)
- ranjankarLv 79 years ago
2 ( c^2 - 121)
USE FORMULA a^2 - b^2 = ( a+b) ( a-b)
2 ( c + 11) ( c- 11) ANSWER
r ( r^2 - 2r - 12) ANSWER
- Anonymous9 years ago
1. 2(c^2 - 121) (just factor out two)
(c + sqrt(11)) (c - sqrt(11)) (Difference of squares).
2. r(r^2 - 2r - 12) (factor out r)
Find the roots using the quadratic formula (I don't think this is factorable)
and then write it in the form r(r + d)(r + e) where d and e are the roots. You should have a negative and a positive root, and the magnitude of the negative root should be larger.
Hope this helps
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- Mike GLv 79 years ago
i) 2c^2-242 = 2(c^2-121) = 2(c+11)(c-11)
ii) r^3-2r^2-12r = r(r^2-2r-12)