In order to find the equation of the line, take into account that the general form of the expression of the line can be written as follow:
y - yo = m(x - xo)
where m is the slope and (xo,yo) is a point of the line.
in this case you have m = -5 and (xo,yo) = (2,-137). Replace the previous values into the general expression of the line and solve for y:
y - (-137) = -5(x - 2)
y + 137 = -5x + 10
y = -5x + 10 - 137
y = -5x - 127
Hence, the equation of the line is y = -5x - 127