y = -4x - 6 and -4x - y - 6 = 0 are both representations of the same linear equation.
The first equation, y = -4x - 6, is in slope-intercept form, where y is the dependent variable, x is the independent variable, -4 is the slope and -6 is the y-intercept. This means that when you graph this equation, the slope of the line will be -4 and the y-intercept will be -6.
The second equation, -4x - y - 6 = 0, is in standard form, where the variables are on one side of the equation and the constants are on the other side. To get this equation, you can move the y term to the other side by adding y to both sides, and then move the constants to the other side by adding 6 to both sides.
Both equations represent the same line. They are just in different forms, one is in slope-intercept form and the other is in standard form.