Explanation:
this just means that the first function with input value x = 0 is calculated. that result becomes the input value x for the second function. and that result becomes the input value x for the 3rd function. and that result is then our result.
to answer a and b we only need to look at the main operation of each function :
the first one uses only basic multiplication and subtraction.
the second one uses squaring.
the third one is a 1/x operation.
a.
since the final result is a negative number (-31), the second function with the square operation cannot be last.
because a square operation always delivers a positive result.
+a × +a = +a²
-a × -a = +a²
remember, for a square operation we multiply the same number by itself. therefore we cannot mix signs like -a × +a, because then they would not be the same numbers anymore.
b.
since the initial input value is 0, the third function (1/x) cannot be the first, because 1/0 is not defined.
c.
because of the "large" -32 term in the first function I guess that this will be the last one to create such a low negative result of -31.
since 1/x cannot be first, (x - 2)² is then first. that makes 1/x second, and (4x - 32) third, as mentioned.
let's try :
x = 0
(x - 2)² = (0 - 2)² = (-2)² = 4
x = 4
1/x = 1/4
x = 1/4
4x - 32 = 4×1/4 - 32 = 1 - 32 = -31
hurrah ! we are correct !