Question 8820
To evaluate (find the value of) the expression: {{{(84/z) - 6}}} for z = 7, you just replace the z in the expression with its eqivalent (7) and do the arithmetic. So, it would look like this:

{{{(84/7) - 6 = 12 - 6}}} = 6


Similarly for {{{48/h)*2}}} for h = 8  Replace the h with 8.

{{{(48/8)*2 = 6*2}}} = 12