The point-slope form of a linear equation is given by the formula:
\[ y - y_1 = m(x - x_1) \]
where:
- \((x_1, y_1)\) is a point on the line,
- \(m\) is the slope of the line.
In your example, the equation given is:
\[ y - y_1 = -3(x - 1) \]
From this, we can identify the slope \(m = -3\) and the x-coordinate of the point \(x_1 = 1\).
To find the missing value \(y_1\), we need to know the y-coordinate of the point on the graph where \(x = 1\). Once we have \(y_1\), we can complete the point-slope form of the equation.
Without additional information about the specific \(y\) value at \(x = 1\), we cannot determine \(y_1\). However, if the graph of the function is available and shows the value of \(y\) at \(x = 1\), insert that value for \(y_1\) to complete the point-slope equation.
If you have the y-coordinate value at \(x = 1\), please provide it so that we can complete the point-slope form. Otherwise, the value remains undetermined until that information is known.