Standard equation for a line is:
Ax + By = C
where A, B and C are integers, and A is positive
Slope-intercept from is:
y = mx + b
where m is the slope and b the y-intercept. Replacing with m = 3 and b = -2, we get:
y = 3x - 2
or
-3x + y = -2
multiplying by -1 at both sides:
3x - y = 2
This equation satisfies the standard form, with A = 3, B = -1 and C = 2