ROVIKULY 2.10 : x^3 – 15x^2 + 75x – 125 = ? (problem with solution)

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

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

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

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

Which equals
x minus 5, all cubed.

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