Line 1 and Line 4 are parallel lines
Solution:
General equation of a line:
y = mx + c
where m is the slope and c is the y-intercept of the line.
<u>To find the slope of each line:</u>
Line 1: 
Slope 
Line 2: 

Add 7 on both sides, we get

Slope 
Line 3: 
Slope 
Line 4: 
Subtract x from both sides, we get

Multiply by
on both sides, we get

Slope 
<em>Two lines are parallel, if their slopes are equal.</em>
From the above slopes,

Therefore Line 1 and Line 4 are parallel lines.