Answer:
A. add 81; 
Step-by-step explanation:
The perfect square formula

Rewrite expression
as follows:

So, to form a perfect square,
is missed.
When we add
we will get

36, because 60 time .4 is 24 so 60 - 24 is 36 so it is 36 dollars.
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Tan 2x - cot x = 0
2tan x / (1 - tan^2 x) - 1/tan x = 0
2tan^2 x - (1 - tan^2 x) = 0
2tan^2 x - 1 + tan^2 x = 0
3tan^2 x - 1 = 0
tan^2 x = 1/3
tan x = + or - 1/√3
The fractions which cannbe formed are: 2/3, 3/2, 2/5, 5/2, 3/5 and 5/3.
Now, we find the products with the third number:
2/3*5= 10/3 = 3.33 > 2
3/2*5 = 15 >2= 7.5 > 2
2/5*3= 6/5 (rejected)
5/2*3 = 15/2 > 2
3/5*2= 6/5 (rejected)
5/3*2 = 15/2 = 7.5> 2