Question

Expand the following
(a) (y+1) ³
(b) (x+4y)³
(c)
$(\frac{1}{2} + \frac{1}{3} b) {}^{3}$

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Answer 1

Step-by-step explanation:

1)

(y+1)³=

(a+b )=a³+b³+3a²b+3ab²

let ,, a=y b=1

=y³+1³+3.y². 1+3.1²

= y³+1+3y²+3y

2)

(x+4y)³

= (a+b )=a³+b³+3a²b+3ab²

= let a=x ,,b=4y

=(x)³+(4y)³+ 3.x².4y+ 3.x.4y²

=x³+64y³+12x²y+48xy²