Question 621707
You can determine if two lines are perpendicular by finding their slopes. The rule is that 2 lines are perpendicular if their slopes are negative reciprocals of each other. So first, re-write the given equations in y=mx+b form so you can easily find the slope (m).

Equation #1:
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{{{y=5-3x}}}
{{{y=-3x+5}}}

The slope of this line is thus -3

Equation #2:
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{{{3x-y=8}}}
{{{-y=-3x+8}}}
{{{y=3x-8}}}

The slope of this line is thus +3

-3 and 3 are NOT negative reciprocals of each other, so these 2 lines are NOT perpendicular.

Note: if you are not sure what negative reciprocal means, slopes such as -3 and 1/3 are negative reciprocals.

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Good Luck,
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