PLEASE HELP ME WITH THESE TWO QUESTIONS IF YOU CAN PROVIDE AN EXPLANATION THAT WOULD ALSO BE GREAT! THANK YOU!

Question 61)  The answer is:  [C]:  " y = - 2x − 1 " .
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Note:  All of the FOUR (4) answer choices are written in "slope-intercept form" ;  that is:  " y = mx + b " ; 
           in which:  "y" exists as a single, stand-alone variable on the far left-side of the equation;  "m" is the slope of the line (may be positive or negative or non-existent)—and is the coefficient of "x" ; and "b" is the "y -intercept" of the line of the equation—and may be positive or negative (or non-existent).
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So; we are to find the equation with:  
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a   "y -intercept" of "-1" ;  AND:

a  "slope of "-2" ; 
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By looking at the answer choices;  Choice [A] is the only option in which:
   "m" (the slope; that is the coefficient of "x"); is equal to "-2" .   So we know that should be our answer.  Also, this is the only answer choice where the value of  "b" ; that is, the "y-intercept" ; is equal to:  "-1" .
    → So; we should know by looking at the choices.  We can further confirm by examining the answer choices to confirm BOTH criteria.
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Question 62)  The answer is:  [A]:  " y − 1 = 3(x − 2)" .
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Explanation:  Looking at the FOUR (4) answer choices, you can see that ALL of the options are written in the "point-slope format" ; that is:  "y − y₁ = m(x − x₁) " 

Given the first of the two points:  "(2, 1) " → "(x₁ , y₁) " ;  in which "y₁ = 1" ; 

The only answer choice with "y - y₁"  being "y − 1"  ;  is:  "Choice:  [A]:
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