Question

write an equation of a line that passes through the points (-2,5) and (1,2)

Answer 1

m=(5-2)/(-2-1)=3/(-3)=-1
y=mx+b is a form all lines can be written in
y=-1x+b we need to know b
we know a point on the line (1,2)
x=1
y=2
2=-1(1)+b
solve for b
2=2+b
b=0
so
equation of the line is
y=-x

Answer 2

oops mistake!
2=-1+b
so b=2+1=3
so equation of the line is y=-x+3