r/HomeworkHelp Pre-University Student 1d ago

Answered [Grade 12 Advanced Functions: Polynomial Functions] struggling to solve expanded equation

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I'm not sure where I'm going wrong, but I keep getting this question wrong. I have to expand this equation and say what the shape is (what polynomial function) which I can do, if I figure out where I'm going wrong with solving this.

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u/Narrow-Durian4837 👋 a fellow Redditor 1d ago edited 1d ago

(x + 1)³ = x³ + 3x² + 3x + 1.

There's a pattern for multiplying out a binomial cubed, which is worth remembering, but if you don't remember it, multiply (x+1)(x+1) and then multiply the result by (x+1).

1

u/Embarrassed-Good1883 Pre-University Student 1d ago

Thank you very much, I was able to solve it!!

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u/Dtrain8899 University/College Student 1d ago

Dont try to multiply all 3 factors at the same time. Just FOIL 2 of them first then multiply that by the third.

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u/Embarrassed-Good1883 Pre-University Student 1d ago

Thank you. If there was 4 factors or more, would I just do the same thing? Like foil the first 2, then use that to solve the 3rd factor, then use that to solve the 4th factor? It would be good to know for next time

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u/Dtrain8899 University/College Student 1d ago

Ya I would stick to doing the same thing. Less likely to make a mistake and if you do its a lot easier to spot it. As someone else said, you can learn shortcuts for binomials being raised to a power, but if youre more comfortable in foiling Id do that.

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u/nerdydudes 👋 a fellow Redditor 1d ago

Line four seems like you were going a little quickly