No, the 2 lines can never ever be both parallel and perpendicular if I'm not mistaken. This is because a set of parallel lines will never touch each other at all. However perpendicular lines are two lines that meet up to get an angle of 90. You cannot have two lines that never touch and touch at the same time.
I would solve the first equation for x and then sub that value into x in the second equation. That's the easiest way. x - 2y = 3 solved for x is x = 2y+3. Now sub that in for x in the second equation: 5(2y+3)+3y=2 and 10y + 15 + 3y = 2. 13y = -13, and y = -1. Now sub that y value into either equation to solve for x: x = 2(-1) + 3 gives us an x value of x = 1. Therefore, your solution to this system is (1, -1), first choice above.
Hi there!

Find the value of 8 by substituting in -18 for g(x):
-18 = 2x - 8
Add 8 to both sides:
-10 = 2x
Divide both sides by 2:
-10/2 = 2x/2
x = -5
Answer: the slope would be 0
Step-by-step explanation: