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Again, it would probably be best to pick some values for x and solve for y, since y is already isolated.

x

y = -½x – 2

(x, y)

y = -½(0)– 2

y = 0 – 2

y = -2

(0, -2)

1

y = -½(1)– 2

y = -½ – 2

y = -2½

(1, -2½)

2

y = -½(2)– 2

y = -1 – 2

y = -3

(2, -3)

Now let's plot them and connect them:

Example 2

Graph the equation x + 3y = 7.

With all equations, it is really up you which variable to solve for, but for this problem it would be easiest to solve for x, since it doesn't have a coefficient.

subtract 3y from each side

simplify

Now, let's plug in some numbers for y and solve for x.

y

x = 7 – 3y

(x, y)

x = 7 – 3(0)

x = 7 – 0

x = 7

(7, 0)

1

x = 7 – 3(1)

x = 7 – 3

x = 4

(4, 1)

2

x = 7 – 3(2)

x = 7 – 6

x = 1

(1, 2)

Since we picked values for y and solved for x, we must be careful to plot them in the correct order, x then y.

Example 3

Graph the equation 2y = 6x.

Let's solve this one for y.

subtract 3y from each side

simplify

Now, let's plug in some numbers for x and solve for y.