#•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"#