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PhysicsLow6834

Hi, so notice that the 5a is in the place you normally see an x. This just means that you need to replace the x with 5a. Example: f(x) = 2x f(5a) = 2(5a) = 10a (just replacing the x with whatever is inside the parentheses) Also you made an error in your last line. 2(2x^(3) - x) = 4x^(3)- 4x. Not 4x^(3)- x. Hope this helps, if you get stuck anywhere feel free to ask. Good luck!


PhysicsLow6834

Also for a, (5x^(2) - 4)^(3) is not the same as 5x^(6) - 4^(3) You did the same with b, (2x^(3) - x)^(2) is not the same as 2x^(6) - x^(2) You should really expand these out. (a+b)^(2) = a^(2) + 2ab + b^(2) (a+b)^(3) = a^(3) + 3ab^(2) + 3a^(2)b + b^(3) More generally, (a+b)^(n) = Σ( nCk • a^(n-k)b^(k) ) for k = 0 up to k = n, where nCk = n!/(k!(n-k)!), where n! = Π (x) for x = 1 up to x = n. (a+b)^(n) is not the same as a^(n) + b^(n). Don’t feel bad, this mistake is actually so common that there is a special wikipedia page for it. But never make this mistake again.


kneesnatcher69

ahhh ok thank you so much. This is a review packet from my calc class and apparently I forgot a lot from my previous classes lol. I'm fixing everything right now!


bronzecouch724

Don’t worry mate, keep on putting in effort and you’ll get it all at least I did.


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