Big Ideas Math: Modeling Real Life, Grade 7
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Big Ideas Math: Modeling Real Life, Grade 7 View details
4. Writing and Solving Proportions
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Exercise 3 Page 208

In an ordered pair, the x-coordinate comes first and the y-coordinate comes second.

Practice makes perfect
In an ( x, y) ordered pair, the first number tells us the x-coordinate of the point and the second number tells us the y-coordinate of the point. To graph A( - 5, - 2), we first find -5 on the x-axis and make a mental note of this grid line. The x-coordinate -5 tells us to move 5 units to the left of the origin — the negative horizontal direction.

Next, we find -2 on the y-axis and follow this grid line until it collides with the grid line from our x-coordinate. The y-coordinate -2 tells us to move 2 units down from the origin — the negative vertical direction.

The point A( - 5, -2) lies on the point at which these two grid lines intersect.