Question

If x – 9 is a factor of x2 – 5x – 36, what is the other factor a. x – 4 b. x 4 c. x – 6 d. x 6

Answer 1

X^2 -5x -36 = x*x -9x+4x -9*4 = x(x-9) +4(x-9) = (x+4)(x-9)

so the second other factor is x+4 so hope that choice wan being x+4 than this will be right just you missed the sign pf plus 

hope this will help you 

Answer 2

Answer:

a ) Other factor will be ( x + 4 ) .

Step-by-step 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 ) .