Answer:
The equations of the lines are y=3 and y=8.
Parallel lines have equal slopes, so if the slopes are opposites, the slopes must be 0.
A line with this slope and passing through (7, 3) has equation y=3.
Explanation:
The above answer statements pretty much speak for themselves. The only opposite numbers that are equal are 0 and -0 = 0, so the slopes must be 0.
A line with a zero slope has a constant y-value, so is of the form ...
y = constant
If it goes through a point with a y-coordinate of 3, then the constant must be 3. The line is ...
y = 3
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If the sum of two numbers is 11 and one of them is 3, the other is 8. So, the parallel line has equation y = 8.