Correct order of terms

Rich16

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Sep 20, 2019
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2
Hi,

My textbook has two problems. First:
-6(x+7)+x(9x+10)-(4-x)

I've simplified to: -6x-42+9x^2+10x-4x
Then collected like terms: 5x-46+9x^2
The answer in the textbook changes the order to: 9x^2+5x-46

Second:

2(1-3x)-4(x+2)
Which would become: 2-6x-4x-8
The answer for this in the book is:
-6-10x

They haven't changed the order here. I know the result will be the same either way, but isn't the convention to have terms with the highest exponents at the start, then constants (eg. x^3+x^2+x+1)? So shouldn't it be -10x-6 (since ^1 next to -10x is implied? I just want to make sure I'm writing it conventionally even when it doesn't affect the result.
 
No, there is no such "convention". It is often done that way but there is no requirement.
 
2(1-3x)-4(x+2)
Which would become: 2-6x-4x-8
The answer for this in the book is:
-6-10x
Yes, the book is correct, all you got to do is combine the "2" and the "-8" to get -6, and -6x and -4x to get -10x so the results is -6-10x
 
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