Line 
represents the graph of 
. Line 
passes through the point 
, and is perpendicular to line . If line represents the graph of 
, then find 
.
+178 Slope of l_1 is -3/4 so slope of l_2 is 4/3 which means l_2 is y=4/3x+b and we get 7 = -20/3+b so b = 41/3 which menans m+b=4/3+41/3 = 15.
