Question

write the coefficient of x square in the expression of (x-5)3 ( 3 is cube)​

Answer 1

coefficient of xsquare in the expression is -15

Answer 2

Answer :

(x - 5)³

Using identity :

(a - b)³ = a³ - b³ - 3ab (a - b)

⇒ (x)³ - (5)³ - 3 * x * 5 ( x - 5 )

⇒ x³ - 125 - 15x ( x - 5 )

⇒ x³ - 125 - 15x² + 75x

⇒ x³ - 15x² + 75x - 125

Here, the coefficient of x² is (-15).