What am I doing wrong?????

latresa31s

Junior Member
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Sep 4, 2005
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135
(3a - 2)(4b + 3)(3x +2)

=6x +9 -4x-6

=6x =5x -6

Or

=(6x +5x -6) (3x + 2)

according to the book I was suppose to find the terms that are underlined first. I am confused as what to do.
 
I'm sorry, but I can't make heads or tails of what you've posted. Please reply with a clear statement of the exercise, exactly as provided to you, along with the instructions, and line-by-line explanations of what you have tried. Thank you.

Eliz.
 
From my book an example problem like this one was under the heading

Multiplying Polynomials with more than two terms




Multiply. (3a – 2)(4b + 1)(b – 5)

I would first multiply any two of the binomials
(3a - 2)(4b + 1)

=12ab +3a -8-2

=(12ab -5 -2)(b -5)

This is where I get stuck.

I do hope this help.
 
I would first multiply any two of the binomials
(3a - 2)(4b + 1)
Right this far
=12ab +3a -8-2
What happened to the b?
=12ab + 3a -8b -2
F____O___I___L

=(12ab -5 -2)(b -5)
What happened to the 3a?
(12ab + 3a -8b -2)(b-5)
Take one term at a time.

b*(12ab + 3a -8b -2) +
(-5)(12ab + 3a -8b -2)

(12ab²+3ab-8b²-2b) +
(-60ab-15a+40b+10)
Gather like terms. Hint: they are ab², ab, b², a, b, and 10
 
all the like terms are not there

Your answer:(12ab²+3ab-8b²-2b) +
(-60ab-15a+40b+10)

Mine:I did what you did. was I suppose to add a exponent of 2 to the -60ab also to 40b.

You gave me the hint and I still did not get that part but I understood the rest.
 
I was multiplying
12ab + 3a -8b -2
by b on the first line and by -5 on the second line. You should get exactly what I got.
Then you gather everything that is a multiplier of ab. That is
3ab and -60ab. You combine them into
-57ab. that is one term in the final answer. Do the same with each of the things I listed.
 
I gave you a list of the terms you should get. Each one will appear once in the correct answer.
 
latresa31s said:
all the like terms are not there
Your answer:(12ab²+3ab-8b²-2b) + (-60ab-15a+40b+10)
Mine:I did what you did. was I suppose to add a exponent of 2 to the -60ab also to 40b.
(12ab²+3ab-8b²-2b) + (-60ab-15a+40b+10)
Geezzz latresa (change that to LaStress!), why don't you keep it SIMPLE?
Remove the brackets:
= 12ab² + 3ab - 8b² - 2b - 60ab - 15a + 40b + 10
rearrange with like terms together:
= 12ab² + 3ab - 60ab - 8b² - 15a - 2b + 40b + 10
combine like terms:
= 12ab² - 57ab - 8b² - 15a + 38b + 10

now WHOA!! It's OVER. Don't try anything else; THAT'S IT!!
 
sorry I was so much trouble and stressful I was stressing my own self. I guess I just the attitude I want never get this stuff and I have been working on this work for about 5 hours and my brain may be tried. Happy to tell you this was my last problem.

You and all the others are a great help to those that don't know this stuff. this is my frist time ever taking algebra. So I do hope next time I use this board I want be sooo, stressing.

Thanks a lot and have a good night.
 
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