Find the standard form of the equation of the line with slope -2 and y-intercept -4.
Choices are:
8x+4y=-16
y=-2x+4
-8x-16y=4
4x+8y=-16
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First find the slope intercept form, which is
y = mx + b
where m = slope and b = y-intercept
So for this problem, m = -2 and b = -4, thus
y = mx + b
becomes
y = (-2)x + (-4)
or
y = -2x - 4
Now we change it to the standard form Ax + By = C
by adding 2x to both sides
y = -2x - 4
2x + y = -4
That's it in simplest standard form! But, alas,
that's not any one of the choices given! However,
if we multiply that equation though by 4, we get
8x + 4y = -16
which is the only choice given that is equivalent
to 2x + y = -4
That IS in general form Ax + By = C, just not in
the simplest general form. Nevertheless,
8x + 4y = -16
is the only choice which could be correct, even
though that is not in simplest possible standard
form. But the other choices are not even
equivalent to 2x + y = -4.
Edwin
