A linear equation has the form y=mx+c.

In the first set you are given m. Substitute the points and then rearrange to find c. So for the first question,

y = -2x+c and (x,y) = (2,1)

1 = -2(2)+c

1=-4+c

1+4 =c

c=5.

y = -2x+5

In the second set you are given 2 points. Call them and , and use the formula , then use the method for the first set.

The first question looks like this:

and

=2

y = 2x+c

3=2(2)+c

3=4+c

3-4 = c

c=-1

y=2x-1