direct variation?

Easiest way to figure it out is to simply plug a number in for x, solve for y.

1-y=2x.

Let x=0

We plug in the number 0 for x.

1-y=2(0)

Then we simplify the 2(0)

1-y=0

Move the y over, because we need to isolate it, or put it by itself. The letter or symbol you isolate MUST be positive.

In order to move the subtracted y over, we do the opposite. The opposite of subtraction is addition. So we add y to BOTH sides becase it is an equation.

1=y

So when x=0, y=1.

Choose a new number for x, x=1.

1-y=2x

1-y=2(1)

1-y=2

1=2+y

1-2=y

-1=y

So when x=1, y=-1.

This is NOT direct variation because as x increases, y DECREASES.