#•color(white)(x)[1/2(x_1+x_2),1/2(y_1+y_2)]#
#"midpoint "=[1/2(-1+7),1/2(-3+1)]#
#color(white)("midpoint ")=[1/2(6),1/2(-2)]=(3,-1)#
#"calculate slope m using the "color(blue)"gradient formula"#
#•color(white)(x)m=(y_2-y_1)/(x_2-x_1)#
#"let "(x_1,y_1)=-1,-3)" and "(x_2,y_2)=(7,1)#
#rArrm=(1-(-3))/(7-(-1))=4/8=1/2#
#"given a line with slope m then the slope of a line"#
#"perpendicular to it is"#
#•color(white)(x)m_(color(red)"perpendicular")=-1/m#
#rArrm_"perpendicular"=-1/(1/2)=-2#
#"the equation of a line in "color(blue)"point-slope form"# is.
#•color(white)(x)y-y_1=m(x-x_1)#
#"where m is the slope and "(x_1,y_1)" a point on the line"#
#"using "m=-2" and "(x_1,y_1)=(-1,-3)" then"#
#rArry+1=-2(x-3)larrcolor(red)"in point-slope form"#
#rArry+1=-2x+6#
#rArry=-2x+5larrcolor(red)"in slope-intercept form"#