Question

answer it's factorisation ​

Answer 1

Answer:

y = -4,5

Step-by-step explanation:

y ^2 - y - 20

= y^2 -5y +4 y -20

= y(y -5) + 4 (y -5)

(y + 4) (y-5) = 0

therefore y = -4,5

Answer 2

Answer:

y² × - 20 = -20y²

so, -5y and +4y are the co-ef

(-5y × +4y = 20y², -5y + +4y = -y²)

y² - 5y +4y - 20 = 0

[Take common]

y(y - 5) + 4(y - 5) =0

(y + 4) (y - 5) = 0

y = -4, y = + 5