SOLUTION: Factor 3z^2+14z +8 I have tried this repeatedly and I keep coming up with an answer that is exactly like the problem

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Factor 3z^2+14z +8 I have tried this repeatedly and I keep coming up with an answer that is exactly like the problem       Log On


   



Question 250004: Factor 3z^2+14z +8
I have tried this repeatedly and I keep coming up with an answer that is exactly like the problem

Found 2 solutions by richwmiller, Edwin McCravy:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
there are several ways to look at this but the simplest is to factor
with 3z as the beginning of one of the factors
we need to come up with 14 and 8 using 3
what are factors of 8 which can combine with 3 to make 14
4*2=8 and 3*4+2=14
let's try (3z+4)(z+2)
that gives us 8 but not the 14 but only 10
let's try (3z+2)(z+4) yes (3*4) +2=14 and 2*4=8


Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
hFactor 3z^2+14z +8
3z%5E2%2B14z%2B8

We try to factor it.


3z%5E2%2B14z%2B8

Multiply the 3 by the 8, get 24.  Write down all the ways
you can multiply two positive integers together to get 24.
They are

1x24
2x12
3x8
4x6

Now since the last sign before the 8 is +, out to the
right of those we ADD those pairs of positive integers:

1x24   1+24=25
2x12   2+12=14
3x8     3+8=11
4x6     6+4=10


Ignoring signs we see that 14 is the coefficient of the
middle term, and that corresponds to factors 2 and 12,
So we must put signs, either + or -, in front of 2z and 12z 
so they will combine to give the middle term, +14z.  We 
can do that by assigning a positive sign to 2z and a 
positive sign to 12z.  So the middle term +14z can be
written as +2z+12z
 
So

3z%5E2%2B14z%2B8

becomes

3z%5E2%2B2z%2B12z%2B8

Factor only the first two terms:

z%283z%2B2%29%2B12z%2B8

Factor the last two terms:

z%283z%2B2%29%2B4%283z%2B2%29

Now notice there is a common binomial factor of
%283z%2B2%29, so we can factor it out:

%283z%2B2%29%28z%2B4%29

That's it!

Edwin

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