Slope-intercept form:
y = mx + b "m" is the slope, "b" is the y-intercept (the y value when x = 0)
Since you know m = 7/2, plug it into the equation
y = 7/2x + b
To find "b", plug in (-12,-9) into the equation
y = 7/2x + b
-9 = 7/2(-12) + b
-9 = -84/2 + b
-9 = -42 + b Add 42 on both sides
33 = b
(if you're not suppose to use slope-intercept form)
Point-slope form:
y - y₁ = m(x - x₁)
m = 7/2
(x₁ , y₁) = (-12,-9)
Plug this into the equation
y - y₁ = m(x - x₁)
y - (-9) = 7/2(x - (-12))