Isolate the x. Root both sides
√x²< √81
x < 9 is your answer
hope this helps
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:

0.90 and I think .9 is another I'm not sure but I tried
12 ) 18
13) 54
14) 28/54 (8weeks x 7 days) = 1/2
18/24 = 3/4
therefore rates not equal
15) 0 and 0 ;1 and 4; 2 and 8;3 and 12