Question

If one of the factors of the polynomial (x – 2y)² + 7(x – 2y) - 18 is

(x - 2y + 9) then the other factor is :
​

Answer 1

Answer:

Let (x−a) be the other factor.

Now, (x+5),(x−a) are factors of the quadratic equation x

2

+x−20

Thus,

(x+5)(x−a)=x

2

+x−20

=>x

2

−ax+5x−5a=x

2

+x−20

=>x(5−a)−5a=x−20

Now, considering the co-efficients of x on the both sides,

5−a=1

=>a=5−1=4

Therefore the other factor is (x−4)