Answer
Approximately $100
Work Step by Step
$m = (105-85)/(7-4)$
$m = 20/3$
$m=20/3$
$105 = 7*20/3+ b$
$105 = 140/3 + b$
$105 - 140/3 = 140/3 + b - 140/3$
$175/3 = b$
$y = 20/3*x + 175/3$
$y = 20/3*6 + 175/3$
$y = 40 + 175/3 $
$y = 40 + 58.33$
$y = 98$