Answer:
a ) Other factor will be ( x + 4 ) .
Explanation:
Given : x²– 5x – 36.if x – 9 is a factor
To find : what is the other factor .
Solution : We have given that x²– 5x – 36.= 0
On factoring x² + 4x - 9x– 36= 0
Taking common x from first two terms and -9 from last two terms .
x ( x + 4) -9 ( x + 4) = 0
on grouping
(x -9) ( x+4) = 0.
Therefore, a ) Other factor will be ( x + 4 ) .