Question 1105519
Plug the values in for x and y.
If both values make the statement true then you have your answer.
Example: (-4,10)
{{{y-5=5(x-7)}}}
{{{10-5=5(-4-7)}}}
{{{5=5(-11)}}}
{{{5=-55}}}
False, so you know that A is not a line containing both (-4,10) and (-7,-5).
There's no need to check point (-7,-5) since the first point already failed.
If the first point yields true, then you must check the second point.
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.
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Follow the same procedure for the remaining letters.