Take into account that a general expression for a linear equation can be written as follow:
y - yo = m(x - xo)
where m is the slope of the line, and (xo , yo) is a point of such a line.
Replace the given values of m and (xo,yo):
m = 4
(xo,yo) = (-3,6)
into the general expression for a linear equation:
y - 6 = 4(x - (-3))
and solve for y:
y - 6 = 4(x - (-3))
y - 6 = 4(x + 3) apply distribution property right side
y - 6 = 4x + 12 add 6 both sides
y = 4x + 12 + 6
y = 4x + 18
the slope-intercept form of a equation of a line is, in general:
y = mx + b
where m is the slope and b the y-intercept
then, by comparing the previous equation with the obtained result, you can notice that the slope-intercept form of the required line is:
y = 4x + 18