How do I work out A & B ?

Answer:
see explanation
Step-by-step explanation:
(a)
Given
x² + 5x + 6
Consider the factors of the constant term ( + 6) which sum to give the coefficient of the x- term ( + 5)
The factors are 3 and 2, since
3 × 2 = 6 and 3 + 2 = 5, hence
x² + 5x + 6 = (x + 3)(x + 2) ← in factored form
(b)
To solve
x² + 5x + 6 = 0 ← use the factored form, that is
(x + 3)(x + 2) = 0
Equate each factor to zero and solve for x
x + 3 = 0 ⇒ x = - 3
x + 2 = 0 ⇒ x = - 2
Answer:
a)
[tex](x + 2)(x + 3)[/tex]
b)
[tex]x = 2 \: or \: x = 3[/tex]
Step-by-step explanation:
a)[tex]{x}^{2} + 5x + 6[/tex]
[tex]= {x}^{2} + 2x + 3x + 6[/tex]
[tex] = x(x + 2) + 3(x + 2)[/tex]
[tex] = (x + 2)(x + 3)[/tex]
b)
[tex]{x}^{2} + 5x + 6 = 0[/tex]
[tex]{x}^{2} + 2x + 3x + 6 = 0[/tex]
[tex]x(x + 2) + 3(x + 2) = 0[/tex]
[tex](x + 2)(x + 3) = 0[/tex]
[tex]so \: either \: x + 2 = 0 \: or \: x + 3 = 0[/tex]
[tex]therefore \: x = - 2 \: or \: x = - 3[/tex]