Question

(y-5) (y+9) is equal to​

Answer 1

Step-by-step explanation:

•Product of (y-5) and (y+9):

(y-5)(y+9)

Of the form (x+a)(x+b)=x²+(a+b)x+ab

= y² +(-5+9)y+(-5)(9)

=y²+4y-45

•Identities:

1. (a+b)²=a²+2ab+b²

2. (a-b)² =a²+b²-2ab

3. a²-b²=(a+b)(a-b)

4. a³+b³+c³=3abc

5.(a+b)³ = a³+b³+3a²b+3ab²

6.(a-b)³ = a³-b³-3ab(a-b)

Answer 2

$\Large{\boxed{\underline{\sf{Hey \: Mates \: !!!!}}}}$

$\rule{200}{2}$

(y - 5)(y + 9) is equal to

→ y(y + 9) - 5(y + 9)

→ y² + 9y - 5y + 9

→ y² + 4y + 9

☯ Factorisation :-

↪ Factorising is the reverse of expanding brackets.

↪ Example:

2y + 6 = 2(y + 3)

So, the factors of 2y + 6 are: 2 and (y + 3).

$\rule{200}{2}$