Algebra help?

Question

I don't get this lesson in my Algebra book:
Factoring ax (squared) + bx + c

Example of a question is:
6b(squared)-11b-2

How can I get help on this or does anybody know of a good website to help in this Algebra lesson.

Answer 1

Your teacher should really have explained this to you, or at least told you where in the text it's explained. The exercise is just about finding two factors that, when multiplied together, will result in the given number.

In your example 6b^2 - 11b - 2 will break down to these factors: (6b+1)*(b-2). If you multiply it out, you'll get the given number, like this:
6b*b = 6b^2
6b*(-2) = -12b
(+1)*b = b
(+1)*(-2) = -2

If you add these all up together, you get 6b^2-12b+b-2=
6b^2-11b-2. Any algebra textbook should explain this - good luck.

Answer 2

Gen EQ : ax (squared) + bx + c = 0

When u compare both eqs
6b(squared)-11b-2 = 0 Here a=6 & b=11 and x=b
Solving value of b
Substitute -11b with -12b+b
6b(squared)-12b+b-2 =0 (Since -12b+b= -11b)
(6b(squared)-12b)+(b-2 )=0
6b(b-2)+1(b-2) = 0 (since 6b(b-2) = 6b(squared)-12b & 1(b-2) = b-2)
(6b+1)(b-2) = 0
6b+1 = 0 ; b = -1/6
b-2 = 0; b = 2
Ans: b=2 or -1/6

Answer 3

fyi... this ^2 means squared
when factoring a polynomial (like ax^2 + bx + c) they want you to make it look like this
(3x +2)(x-1)...just an example
when we expand my example we have to use
F (multiply the First two terms together...3x times x)
O (multiply the two Outside terms together...3x times -1)
I (multiply the two Inside terms together... +2 times x)
L (multiply the two Last terms together...+2 times -1)
so use FOIL.
my example would give us:
3x^2 - 3x + 2x - 2 ....the two inner terms are both just x's so we can put them together to get -x.
3x^2 -x -2 <---polynomial like your question!
your problem needs you to do the opposite of what i did in the example...this is harder because the two inner terms usually get put together.

your question:
6b^2 -11b - 2
we know that we use the F to get the 6b^2 (we have to multiply the First terms)
that could be either:
(6b ****)(b ******) or (3b ****)(2b *****) or the same two possibilities with - signs in front.
we also know that we use the L to get the -2 (we have to multiply the Last terms)
that could be either:
(**** -1)(**** +2) or (**** +1)(**** -2) or the numbers can switch places
now we have to combine all our possilities to find which combination will give us the -11x in the middle.
it ends up being:
(6b +1)(b -2)

a tough lesson to type out but i hope it helps

Answer 4

in terms of graphing that, you would get a result of a u-shaped line called a parabola. the ax(squared) thingy is the standard formula. I f you solve it, you get the x-intercepts of the graph

Answer 5

Have fun.

http://mathworld.wolfram.com/QuadraticEquation.html