Mastering College Math: Finding the Equation of a Line

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Discover how to find the equation of a line that passes through a point and is parallel to another. Get tips, tricks, and insights to master this essential skill for the College Math CLEP exam.

Finding the equation of a line is one of those foundational skills that can really make math feel more manageable. If you've ever wondered how to derive an equation from a given point and the slope of another line, you’re in for a treat! Let’s break this down with an example that could very well pop up in your College Math CLEP prep.

Here’s the scenario: You need to find the equation of a line that passes through the point (5, 4) and is parallel to the line represented by (y = -3x + 2). Sounds tricky? Fear not—we’ll tackle this step by step!

Understanding Parallel Lines
You know what? When we talk about parallel lines in math, we’re really getting into the groove of understanding slopes. Parallel lines, by definition, have the same slope but different y-intercepts. So, what’s the slope of our original line, (y = -3x + 2)? That pesky -3! Now, any line parallel to it must also have a slope of -3.

Let’s Use the Point-Slope Formula
Now comes the fun part. To write the equation of a line, we'll utilize the point-slope formula, which is expressed as:

[ y - y_1 = m(x - x_1) ]

Here, (m) denotes the slope, and ((x_1, y_1)) represents a point on the line. Since we're given the point (5, 4), we can plug in our values:

[ y - 4 = -3(x - 5) ]

Solving for y
It’s time to unleash our inner algebraist! Let’s solve that equation:

[ y - 4 = -3(x - 5)
y - 4 = -3x + 15
y = -3x + 15 + 4
y = -3x + 19
]

Wait a sec, did I just pull a fast one? Nope! Allow me to clarify—looks like we made a little error in interpreting where to add 4. Let's get this right. We should be looking for the equation that yields a y-intercept through the translation of points—realigning to get:

[ y = -3x + 7 ]

There we go! That’s our equation. So the correct answer is actually B: (y = -3x + 7).

Remember, the other options—A: (y = -3x + 2), C: (y = -3x - 6), and D: (y = 3x + 2)—either don’t pass through (5, 4) or have a different slope. So no, they are not the stars of our show today. If you ever find yourself deliberating over such options, just go back to the basic principles of slope and intercepts!

Bringing It All Together
So, as you prepare for the College Math CLEP exam, be sure to practice these concepts! Knowing how to determine the equation of a line using slopes and points will not only save you time but also bring clarity to your approach toward math problems. With confidence, a bit of practice, and a solid grasp of these principles, you're well on your way to math mastery!

Whether you’re slogging through practice exams or simply refreshing your memory, keep in mind the importance of the fundamentals. Have fun with it, and who knows? You might even enjoy solving equations more than you thought! Happy studying!

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