Question

A line has unit slope and passes through point origin (0,0) . What is the equation of the line?The answer options are:
a. y = 0
c. y = -xB) x = 0
d. y = x

Answer 1

The answer is:  [D]:  " y = x " .
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Note:  The "slope-intercept form" of a line is in written in the following format:
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    " y = mx + b " ;
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in which: 
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                   "y" is "isolated as a single variable" on the left-hand side of the equation the equation; 
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                   "m" is the slope of the line;
                          and is the coefficient of "x" ;
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                   "b" is the "y-intercept" of the line;
                         that is, "b" is the "x-coordinate" of the point
                         on the line of the equation at which "y = 0" ;
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 We are given:  "a unit slope" ; that is: a slope of "1" ;  

           So, " m = 1 " ;
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and that the line passes through the point:  " (0, 0) " .
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So,  " b = 0 " ;
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 So, we can write this as:  "y = 1x + 0 " ;

As a practical matter —and by convention — we can eliminate the   "+ 0"  ;  and we have:
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 " y = 1x " ;  and long the same guidelines; we can write as:
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 " y = x " ;  which is:  Answer choice:  [D] .
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