Step-by-step explanation:
in which form do you need the equation ?
I just go ahead with the most usual one - the slope-intercept form :
y = ax + b
"a" is the slope of the line, "b" is the y-intercept, which is the y-value when x = 0 (so, the point where the line intercepts the y-axis).
the slope is always the ratio
y coordinates difference / x coordinates difference
when going from one point on the line to another point.
here we go e.g. from (2, 1.5) to (-5, 36.5).
x changes by -7 (from 2 to -5).
y changes by +35 (from 1.5 to 36.5).
the slope (a) is therefore +35/-7 = -5.
the equation looks already like this
y = -5x + b
"b" we get by using one of the points (its x-/y-coordinates) in the half-finished equation. I pick (2, 1.5) :
1.5 = -5×2 + b = -10 + b
b = 11.5
and the full equation is
y = -5x + 11.5
