a.
[tex]ab.am = 1 \\ 4 \times \: a \: = 1 \\ a = \frac{1}{4} = 0.25
[/tex]
b.
[tex]ab.am = - 1 \\ 4 \times am = - 1 \\ a m = \frac{ - 1}{4} = 0.25
[/tex]
c.
[tex]ab.am = - 1 \\ 4 \times am = - 1 \\ a m = \frac{ - 1}{4} = 0.25
[/tex]
d.
[tex]ab \times am = 0 \\ 4 \times am = 0\\ am = \frac{0}{4} = 0[/tex]
e.
[tex]ab \times am = 0 \\ 4 \times am = 0 \\ am = \frac{0}{4} = 0[/tex]
