How do you expand this expression?
(3a-b)^3
(3a-b)^3
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There's actually a rule that (a-b)^3 will equal a^3 - 3(a^2)b + 3a(b^2) - b^3.
So (3a-b)^3
would be:
27a^3 - 9ba^2 + 3ab^2 - b^3.
So (3a-b)^3
would be:
27a^3 - 9ba^2 + 3ab^2 - b^3.
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the ^3 means cubed, or multiplied by itself 3 times
(3a - b)^3
(3a - b)(3a - b)(3a - b)
(9a^2 - 3ab - 3ab + b^2)(3a - b)
(9a^2 - 6ab + b^2)(3a - b)
27a^3 - 9a^2b - 18a^2b + 6ab^2 + 3ab^2 - b^3
27a^3 - 27a^2b + 9ab^2 - b^3
(3a - b)^3
(3a - b)(3a - b)(3a - b)
(9a^2 - 3ab - 3ab + b^2)(3a - b)
(9a^2 - 6ab + b^2)(3a - b)
27a^3 - 9a^2b - 18a^2b + 6ab^2 + 3ab^2 - b^3
27a^3 - 27a^2b + 9ab^2 - b^3
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(3a-b)3=3*3a-3*b=9a-3b we wil multiply 3 to each member of brackets
sorry if there is a grammar mistake I don't know english well.
sorry if there is a grammar mistake I don't know english well.
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whats ^ called?