The Cartesian Coordinate Plane 173
vertical distance (up or down) of the point P from the x-axis. If y is positive,
P is above the x-axis; if y is negative, it is below the x-axis.Problem Name the ordered pair of integers corresponding to point A in
the coordinate plane shown.10yAx9 8 7 6 5 4 3 2 1–10–9–8–7–6–5–4–3–2–1 12345678(0, 0)
–1^910
–2
–3
–4
–5
–6
–7
–8
–9
–100Solution
Step 1. Determine the x-coordinate of A.
The point A is 7 units to the left of the y-axis, so it has x-coordinate −7.Step 2. Determine the y-coordinate of A.
The point A is 4 units above the x-axis, so it has y-coordinate 4.Step 3. Name the ordered pair corresponding to point A.
(−7, 4) is the ordered pair corresponding to point A.Two ordered pairs are equal if and only if their corresponding coordi-
nates are equal; that is, (a, b) = (c, d) if and only if a = c and b = d.