"the equation of a line in "color(blue)"slope-intercept form"the equation of a line in slope-intercept form is.
•color(white)(x)y=mx+b∙xy=mx+b
"where m is the slope and b the y-intercept"where m is the slope and b the y-intercept
"to calculate m use the "color(blue)"gradient formula"to calculate m use the gradient formula
•color(white)(x)m=(y_2-y_1)/(x_2-x_1)∙xm=y2−y1x2−x1
"let "(x_1,y_1)=(3,17)" and "(x_2,y_2)=(5,29)let (x1,y1)=(3,17) and (x2,y2)=(5,29)
rArrm=(29-17)/(5-3)=12/2=6⇒m=29−175−3=122=6
rArry=6x+blarrcolor(blue)"is the partial equation"⇒y=6x+b←is the partial equation
"to find b substitute either of the 2 given points into"to find b substitute either of the 2 given points into
"the partial equation"the partial equation
"using "(3,17)" then"using (3,17) then
17=18+brArrb=17-18=-117=18+b⇒b=17−18=−1
rArry=6x-1larrcolor(red)"in slope-intercept form"⇒y=6x−1←in slope-intercept form
rArrb=" y-intercept "=-1⇒b= y-intercept =−1