Answer:


Step-by-step explanation:
Given

Solving (a): Write as inverse function

Represent a(d) as y

Swap positions of d and y

Make y the subject


Replace y with a'(d)

Prove that a(d) and a'(d) are inverse functions
and 
To do this, we prove that:

Solving for 

Substitute
for d in 




Solving for: 

Substitute 5d - 3 for d in 

Add fractions



Hence:

9514 1404 393
Answer:
-4 1/8
Step-by-step explanation:
Many people find it easier to factor out -1, then do the addition. The fractions need a common denominator before they can be added. A suitable denominator that is a multiple of both 4 and 8 is 8.
The fraction 1/4 = (1/4)(2/2) = (1·2)/(4·2) = 2/8.
__
So, the problem can be rewritten as ...
-(1 7/8 +2 2/8)
= -((1+2) +(7/8 +2/8))
= -(3 +9/8)
The fraction 9/8 is an improper fraction equal to 8/8 +1/8 = 1 1/8. Then the sum is ...
-(3 +1 1/8) = -4 1/8
Answer: 6
Steps:
7 + 11 + 0 = 18
18/3 = 6
16-A 18-B 19-D (not 100% sure on 16)