Answer:
3.
a=-1
a=-2
5.
n=-6
n=-3
8.
n=-5
n=-3
Step-by-step explanation:
3. separate into probable cases
[tex]a + 2 = 0\\ a + 1 = 0[/tex]
5.
[tex] {n}^{2} + 6n - 3n - 18 = 0 \\ [/tex]
factor out n from the expression
factor out -3 from the expression
[tex]n \times (n + 6) - 3(n + 6) = 0[/tex]
factor out n+6 from the equation
[tex](n + 6) \times (n - 3) = 0[/tex]
separate into probable cases
[tex]n + 6 = 0\\ n - 3 = 0[/tex]
solve the equations
[tex]n = - 6 \\ n = 3[/tex]
8.
[tex]n ^{2} + 5n + 3n + 15 = 0[/tex]
factor out n and 3 from the expression
[tex]n \times (n + 5) + 3(n + 5) = 0[/tex]
factor out n+5
[tex](n + 5) \times (n + 3) = 0[/tex]
separate into probable cases
[tex]n + 5 = 0 \\ n + 3 = 0[/tex]
solve the equations
[tex]n = - 3 \\ n = - 3[/tex]
