To find the slope of the equation 9x + 3y = 15, we will first rewrite the equation in the slope-intercept form, which is y = mx + b. In this form, m refers to the slope of the line.
Here are the steps to isolate y:
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Start with the original equation:
9x + 3y = 15
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Subtract 9x from both sides to isolate the 3y term:
3y = -9x + 15
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Now, divide every term by 3 to solve for y:
y = -3x + 5
Now that the equation is in the slope-intercept form, we can identify the slope m directly from the equation y = -3x + 5.
The slope of the line is thus -3.
This means that for every unit increase in x, the value of y decreases by 3 units, indicating a negative correlation between x and y.
In summary, the slope of the equation 9x + 3y = 15 is -3.