ROVIKULY 2.08 : x^3 + 15x^2 + 75x + 125 = ? (problem with solution)

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Transcript:
Please factor
x cubed
plus 15 x squared
plus 75 x
plus 125.

FORMULA:
a cubed
plus 3 a squared b
plus 3 a b squared
plus b cubed
equals
a plus b, all cubed.

SOLUTION:
x cubed
plus 15 x squared
plus 75 x
plus 125
equals
x cubed
plus 3 times 5 times x squared
plus 3 times 25 times x
plus 125.

Which equals
x cubed
plus 3 times x squared times 5
plus 3 times x times 5 squared
plus 5 cubed.

Which equals
x plus 5, all cubed.

ANSWER:
x cubed
plus 15 x squared
plus 75 x
plus 125
equals
x plus 5, all cubed.
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