To determine if Annie's graph of the equation \(3x + y = 10\) is correct, we can analyze the equation.
First, we can rewrite the equation in slope-intercept form (y = mx + b):
\[ y = -3x + 10 \]
From this form, we can see that:
- The y-intercept (b) is 10, which means the line crosses the y-axis at the point (0, 10).
- The slope (m) is -3, which indicates that for every 1 unit increase in x, y decreases by 3 units.
Now, we can check the points mentioned. The line passes through (0, 10), which confirms that the y-intercept is correct.
Next, we can check the point (1, 7):
Substituting \(x = 1\) into the equation: \[ y = -3(1) + 10 = -3 + 10 = 7 \]
The point (1, 7) also satisfies the equation, indicating that the slope is indeed correct as the point lies on the line.
Therefore, Annie has correctly plotted both the y-intercept and the slope of the line.
The correct answer is:
3.