Question 1184566
Find k so that the line through (5,-2) and(k,2) is parallel to 16x+21y=42
<pre>Pay NO ATTENTION to the response from the other person.
You'll NEVER get the correct answer with his "interpretation" of the required equation's slope, namely{{{- 21/16}}}!
                   {{{matrix(3,3, 16x + 21y, "=", 42, 21y, "=", - 16x + 42, y, "=", ((- 16)/21)x + 42/21)}}}

Slope of parallel line, or {{{matrix(1,3, m, "=", - 16/21)}}} 

Line through points (5, - 2) and (k, 2) also has a slope (m) of {{{- 16/21}}}
                                      
                                       We then get: {{{matrix(3,3, (2 - - 2)/(k - 5), "=", - 16/21, 4/(k - 5), "=", - 16/21, 1/(k - 5), "=", - 4/21)}}}
   4(k - 5) = - 21 ------- Cross-Multiplying
    4k - 20 = - 21
         4k = - 1
         {{{highlight_green(matrix(1,3, k, "=", - 1/4))}}}

CORRECTED!</pre>