Question 1090055
slope = rise / run = {{{ (y[1]-y[0]) / (x[1]-x[0]) }}} 

 {{{ (7 - p) / (8 - 4) = 2 }}}
 {{{ 7  - p = 8 }}}
 {{{   -p = 1 }}}
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Ans: {{{ highlight( p = -1 )}}}
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Check:   (7 - (-1)) / (8 - 4) = 8 / 4 = 2