How do you write (6x^3 − 8x − 5) + (3x^3 + 6x + 2)(6x3−8x−5)+(3x3+6x+2) in standard form?

1 Answer
PJ
Jul 2, 2018

9x^3-2x-39x3−2x−3

Explanation:

Don't forget to get the signs right.
If the sign before the second bracket was a minus then you would have to multiply through by -1.
( i.e. everything in the second brackets would change sign when the brackets are removed)
(+- makes -, -+ makes -, ++ makes +, -- makes +)

Group all terms of the same type together
(x^3x3 can only be added to x^3x3 etc.)
Note: this is not the same if multipying (e.g.6x^3*3x^2 = 18x^56x3⋅3x2=18x5)

Start with unknowns of highest power, end with constants:

6x^3+3x^3-8x+6x-5+26x3+3x3−8x+6x−5+2

Simplify:

9x^3-2x-39x3−2x−3

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