confused when 3(2a-1)-2(5a+1)+4(3a+4) should be neg or pos
- Thread starter berendsa
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Re: HELP
Hi Berendsa:
This type of confusion goes away after you've worked through dozens of similar algebraic operations.
In the meantime, you can try a method that involves breaking the expression into smaller steps, and then assembly the results after you do the multiplications.
Can you do the following?
3(2a - 1) = ?
-2(5a + 1) = ?
4(3a + 4) = ?
If you can write down the answers to these three questions, then you will have all of the parts that you need to put together a single string of terms to combine (simplify). Here's an example of what I mean.
7(2x + 1) - 4(3x + 2) - 3(9x - 5)
7(2x + 1) = 14x + 1
-4(3x + 2) = -12x - 8
-3(9x - 5) = -27x + 15
Putting the results back together gives me
14x + 1 - 12x - 8 - 27x + 15
Next, I would combine "like" terms by thinking of this expression with the like terms associated (i.e., next to each other).
(14x - 12x - 27x) + (1 - 8 + 15)
Please let us know what SPECIFIC questions you have IF you're still stuck on what to try.
Cheers,
~ Mark
berendsa said:
Hi Berendsa:
This type of confusion goes away after you've worked through dozens of similar algebraic operations.
In the meantime, you can try a method that involves breaking the expression into smaller steps, and then assembly the results after you do the multiplications.
Can you do the following?
3(2a - 1) = ?
-2(5a + 1) = ?
4(3a + 4) = ?
If you can write down the answers to these three questions, then you will have all of the parts that you need to put together a single string of terms to combine (simplify). Here's an example of what I mean.
7(2x + 1) - 4(3x + 2) - 3(9x - 5)
7(2x + 1) = 14x + 1
-4(3x + 2) = -12x - 8
-3(9x - 5) = -27x + 15
Putting the results back together gives me
14x + 1 - 12x - 8 - 27x + 15
Next, I would combine "like" terms by thinking of this expression with the like terms associated (i.e., next to each other).
(14x - 12x - 27x) + (1 - 8 + 15)
Please let us know what SPECIFIC questions you have IF you're still stuck on what to try.
Cheers,
~ Mark