First we are going to express both equation in terms of

to compare their slopes:
For our first equation:



For our second equation:


So now we have our system of equations in terms of y:

Notice that the slope, the coefficient of

, in both equations is the same: 1, and if tow linear equations have the same slope, they are parallel.
We can conclude that we can classify the system of equations as
parallel.
Given is square root of a negative real number, i.e.
When we find square root of positive real numbers, we get Real answers.
But when we find square root of negative real numbers, we get Imaginary answers. To solve them, we can split the given negative number into product of -1 and the number itself but with positive sign. e.g. -4 = -1 x 4.
For square root of -1, we use english letter 'i' called Imaginary unit i.e. 
Now we can use -0.25 = -1 x 0.25

Hence, "0.5i" is the final answer.
If the required difference is 600 mi, lets start of counting by 10s and multiplying the current number
800-700 = 100
1600-1400 = 200
2400-2100 = 300
3200-2800 = 400
4000-3500 = 500
4800-4200 = 600
if 60 hours pass, they will be 600 miles away from each other.
counting by 10 each time will help with problems like or similar to this.
so it'd be 600 / 3 which gives you 200.00 that's what each person paid a day given that there's 5 five times 200 is one day 1000.00x 8 = ($8000.00) for 5 people for 8 days