(a+b)^3 = a^3 + 3a^2 b + 3a b^2 + b^3
(a+b)^3 = a^3 + b^3 + 3ab(a+b)
re-arranging:
a^3 + b^3 = (a+b)^3 - 3ab(a+b)
don't know what all that other stuff is supposed to be
Read the following proof of the polynomial identity a3+b3=(a+b)3−3ab(a+b).
Step 1: a3+b3=a3+3a2b+3ab2+b3−3ab(a+b)
Step 2: a3+b3=a3+3a2b+3ab2+b3−3a2b−3ab2
Step 3: a3+b3=a3+3a2b−3a2b+3ab2−3ab2+b3
Step 4: a3+b3=a3+b3
Match each step with the correct reason.
Commutative Property of Addition
Binomial Theorem
Distributive Property
Commutative Property of Multiplication
Associative Property of Addition
Associative Property of Multiplication
Combine like terms
1 answer
1 answer