Question

Does anyone know how to answer this?

Answer 1

Answer:  Yes.  The answer is:  [C]:  "1 " .
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Explanation:
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The equation for a line, in "slope-intercept format" , is:
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                      →    y = mx + b ;
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                 in which "b" = the y- intercept; or the value of 'x' when "y = 0" ; 
                               "m" = the slope; which is also the coefficient of "x". 
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In "slope-intercept format", the "y" remains isolated on the left-hand side of the equation, with no "coefficient" (other than the "implied coefficient" of "1").
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So, if the two particular lines are parallel, and we know that the slope is "1" for EACH line; (that is, "m = 1" for each line);  then the PRODUCT of the two slopes is:
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                        →    m²   =  m * m  =  1²  =  1 * 1  =  1 .
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                        →  The answer is: Answer choice: [C]:  "1" .
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