How do I solve 3x+4y=0? Please don't just give me the answer because I won't learn how to do this on my own.

1 answer

Sure! I'd be happy to help you understand how to solve the equation \(3x + 4y = 0\). The goal is to express one variable in terms of the other. Let's go through the steps together.

Step 1: Choose a Variable to Isolate

You can choose to isolate either \(x\) or \(y\). For this example, let's isolate \(y\).

Step 2: Rearrange the Equation

Starting with the equation:

\[ 3x + 4y = 0 \]

We'll move \(3x\) to the other side by subtracting \(3x\) from both sides:

\[ 4y = -3x \]

Step 3: Solve for \(y\)

Now, to get \(y\) by itself, divide both sides by \(4\):

\[ y = \frac{-3x}{4} \]

Step 4: Understand the Relationship

At this point, we have expressed \(y\) in terms of \(x\). This means that for any value of \(x\), you can find the corresponding value of \(y\) by using the formula \(y = \frac{-3x}{4}\).

Graphing the Equation

You can also think about this equation in a geometric sense. The equation \(3x + 4y = 0\) represents a line in the xy-plane. The slope of the line can be found from the rearranged equation \(y = \frac{-3}{4}x\), which tells us that for every increase of \(4\) in \(y\), \(x\) decreases by \(3\).

Step 5: Find Specific Points

If you want to find specific points on the line, you can plug in different values for \(x\) and calculate the corresponding \(y\):

  1. If \(x = 0\): \[ y = \frac{-3(0)}{4} = 0 \quad \Rightarrow \quad (0, 0) \]

  2. If \(x = 4\): \[ y = \frac{-3(4)}{4} = -3 \quad \Rightarrow \quad (4, -3) \]

  3. If \(x = -4\): \[ y = \frac{-3(-4)}{4} = 3 \quad \Rightarrow \quad (-4, 3) \]

Summary

By choosing one variable to isolate, rearranging the equation, and solving for that variable, you can find a relationship between the two variables. In this case, \(y\) is expressed in terms of \(x\), and you now have a way to calculate values based on the equation.

As long as you remember these steps, you'll be able to solve similar equations on your own!