Question

Does anyone know at this means:

substitute numerical values into formulae and expressions and use priority of operations, including brackets.
THX
MEEEEEEE

Answer 1

Let's say x = 16.  In the equation 4 + x(3/x) then you use 16 instead of x.  So it would look like 4 + 16(16/3).  4 plus 16 times 16 divided by 3.