Expression 18: "y" equals "m" Subscript, 1 , Baseline left parenthesis, "x" minus "D" Subscript, 1 , Baseline , right parenthesisy=m1x−D1
18
Expression 19: "y" equals "m" Subscript, 2 , Baseline left parenthesis, "x" minus "B" Subscript, 1 , Baseline , right parenthesis plus "B" Subscript, 2 , Baseliney=m2x−B1+B2
19
Expression 20: "m" Subscript, 1 , Baseline left parenthesis, "x" minus "D" Subscript, 1 , Baseline , right parenthesis equals "m" Subscript, 2 , Baseline left parenthesis, "x" minus "B" Subscript, 1 , Baseline , right parenthesis plus "B" Subscript, 2 , Baselinem1x−D1=m2x−B1+B2