Question (18):
Answer: (A) All of the following
(I am using 
in place of conj(z)
Question (19):
Answer: (B) -7
modulus of -7 is sqrt(49)=7
the other choices are all < 7
Answer:
When two functions combine in a way that the output of one function becomes the input of the other, the function is a composite function.
Step-by-step explanation:
In mathematics, the composition of a function is a step-wise application. For example, the function f: A→ B & g: B→ C can be composed to form a function that maps x in A to g(f(x)) in C. All sets are non-empty sets. A composite function is denoted by (g o f) (x) = g (f(x)). The notation g o f is read as “g of f”
We have equation:
t=20x+31
x is number of years after 1997.
To calculate number of laptops in 2005:
x=2005-1997
x=8
t=20*8+31
t=160+31
t=191
In year 2005 school had 191 laptops.
