Add 5 then add 4 is the sequence
The first answer is that the system represents 2 lines. They are two parallel lines.
For the second question, it just represents 1 line. In this case, the two lines are right on top of each other. This is because they are the same equation, just in different forms.
First subtract 9/4 from each side
1/2b=-2/4
Simplify the 2/4
1/2b=-1/2
Divide each side by 1/2
b = -1