find the initial value of the linear function, given that the rate of changes is m = -4/7, and (14,3) is and (x,y) value of the linear function.

1 answer

To find the initial value (or y-intercept) of the linear function when given a slope \( m = -\frac{4}{7} \) and a point \( (x, y) = (14, 3) \), we can use the point-slope form of a linear equation:

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

Here, \( (x_1, y_1) \) is the point \( (14, 3) \), and \( m = -\frac{4}{7} \). Plugging in the values:

\[ y - 3 = -\frac{4}{7}(x - 14) \]

Now, we can solve for \( y \) to put the equation in slope-intercept form \( y = mx + b \):

\[ y - 3 = -\frac{4}{7}x + \frac{4}{7} \cdot 14 \]

Calculating \( \frac{4}{7} \cdot 14 \):

\[ \frac{4 \cdot 14}{7} = \frac{56}{7} = 8 \]

So the equation becomes:

\[ y - 3 = -\frac{4}{7}x + 8 \]

Adding 3 to both sides:

\[ y = -\frac{4}{7}x + 8 + 3 \]

\[ y = -\frac{4}{7}x + 11 \]

In this equation, the y-intercept (initial value) is:

\[ b = 11 \]

Therefore, the initial value of the linear function is 11.