Question 814094
FIND SLOPE, m.
Vertical change divided by horizontal change, {{{m=(8-5)/(2-1)=highlight(3)}}}


FIND VERTICAL AXIS INTERCEPT, b.
General form, same as slope-intercept form, {{{y=mx+b}}},
{{{b=y-mx}}}.
Substitute known m and either point,
{{{b=5-3*1}}}
{{{b=5-3}}}
{{{highlight(b=2)}}}


FINISH EQUATION.
referring to y=mx+b, using the now found values,
{{{highlight(y=3x+2)}}}