Question 1103948
To check, just plug in the (x, y) = (1,-7) values to see if the equation holds:
When writing I like to put a question mark above the equal sign, but here I will use =?= 
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       -7  =?=  5(1) - 7
       -7  =?=   -2      
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NO  (1, -7) does not make the equation true!
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I hope you now understand how to do these.