Given the slope and point, use point - slope form to find the equation of the line:
[tex]y - y _{1}=m(x-x _{1} ) [/tex]
m = 2
[tex](x _{1} ,y _{1} )[/tex] = (2, -1)
Substitute the give values to the point-slope form:
y - 2 = 2 [x - (-1)]
y - 2 = 2 (x + 1)
y - 2 = 2x + 2
y = 2x + 2 + 2
y = 2x + 4 ⇒ slope-intercept form y = mx + b
Equation of the line in standard form ax + by + c = 0:
-2x + y = 4
-1 (-2x + y = 4) -1
2x - y = -4
2x - y + 4 = 0
Equation of the line in general form, ax + by = c
2x - y = -4