Question

solve Simplify a³-(a+1)³​

Answer 1

Answer:

$- 3a {}^{2} - 3a - 1$

Step-by-step explanation:

$a {}^{3} - (a + 1) {}^{3}$

Using $(x + y) {}^{3} = x {}^{3} + 3x {}^{2}y + 3xy {}^{2} + y {}^{3}$expand the expression

$= > a {}^{3} - (a {}^{3} + 3a {}^{2} + 3a + 1)$

When there is a - in front of an expression in parenthesis, change the sign of each term in the expression.

$= > a {}^{3} - a {}^{3} - 3a {}^{2} - 3a - 1$

Since two opposites add upto zero, remove them from the expression

$= > - 3a {}^{2} - 3a - 1$