We can either convert them to decimals or to fractions
if decimals
2/3=0.66666666
4/5=8/10=0.8
so the order is
-0.6, 0.65, 0.66, 0.8 or
-0.6, 0.65, 2/3, 4/5
if conver to fractions then
since -0.6 is negative, it is smallest, no need to convert
0.65=65 hundreths=65/100
2/3=66/99=prety close
4/5=8/10=80/100
order is
-0.6, 65/100, 66/99, 80/100 or
-0.6, 0.65, 2/3, 0.8
Answer:

Step-by-step explanation:
Given

Required
Determine the solution
Since b is a perfect square, the equation can be expressed as:

Apply difference of two squares:

Split:

Remove brackets:

Make a the subject in both equations

The solution can be represented as:

Any of the 4 people can take the first seat
since it gets occupied by one person , the next seat can be occupied by any of the remaining 3
similarly, the next one has 2 possibilities and the last seat can only be occupied by the man who is left
so by the principal of multiplication, no. of ways equals 4! = 4×3×2×1 = 24 ways