since the line is a straight line, the equation will be a linear equation and hence it will be y=mx+c
first, find the gradient (m) :
(y2-y1)/(x2-x1) = [1-(1)]/(-2-6)
= 2/-8
= -¼
sub. in y, x and m values to find c
1 = ¼(-2) + c
1 = -½ + c
c = 1 ½
hence the equation is y = -¼x + 1 ½
