First substitute the variables f and z,
[tex] - 8(6) + \frac{12}{ - 4} [/tex]
then .... do
[tex] - 8 \times 6 = - 48[/tex]
and
[tex] \frac{12}{ - 4} = - 3[/tex]
and Lastly
[tex] - 48 + - 3 = - 51[/tex]
remember negitive and negative is always negitive if adding and subtracting, not multiplying and division
