Cube of a binomial: (a+b)³ = (a+b)(a+b)(a+b)
MULTIPLY USING DISTRIBUTIVE PROPERTY
= (a² + 2ab + b²)(a+b)
= a³ + 2a²b + ab² + a²b + 2ab² + b³
COMBINE SIMILAR TERMS
(a+b)³ = a³ + 3a²b + 3ab² + b³
From the given: (7 +c )³
we let:
a = 7
b = c
Then substitute to the final equation:
(7 + c)³ = (7)³ + (3)(7²)(c) + (3)(7)(c²) + (c³)
= 343 + 147c + 21c² + c³
= c³ + 21c² + 147c + 343 ANSWER...
