Math Is Fun Forum

Heidi

Guest

Factoring completely

#1. 3Y^3 - Y^2 -21Y +7
(3Y^3-Y^2) -(21Y +7)
y^2(3Y -1) -7(3Y -1)
Answer = (Y^2 -7)(3-1)^2

#2. T^3 -T^2- 16T +16
(T^3-T^2)-(16T-16)
T^2 (T-1) - 16(T-1)
T^2-16 (T+1)^2
(T-4)^2(T-1)^2

I hope you can understand what I mean...is my son on the right track with #!... and did he try too much on #2? Thanks for the help...this is what my son has for work on his paper and we plan on going over it tomorrow morning about 6:30 am but I'm not sure if he's got the right idea or not. And don't want to mess him up if he's right! All the reat of his assingment seem right but thiese were the 2 hardest problems... thanks for any and all help! Mom:(

ryos

Member

Registered: 2005-08-04

Posts: 394

Re: Factoring completely

For #1, he's almost there. In factoring (3y-1) out, he doesn't need to square it. So, the answer is (y² - 7)(3y - 1)

#2 suffers from the same problem. And, the difference of squares isn't factored quite right. So, the answer is (T - 4)(T + 4)(T - 1).

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El que pega primero pega dos veces.

4littlepiggiesmom

Member

Registered: 2006-01-09

Posts: 42

Re: Factoring completely

Thanks a bunch I had just gotten the first one to work when stuck with multiplication but the second one I could get past the (T-1) Have a great day! Thanks again! Mom