$P(-6,-8) ;$ slope $\frac{5}{4}$

Step 1 ：Given a point P(-6,-8) and a slope of \(\frac{5}{4}\).

Step 2 ：The general form of a line is \(y = mx + b\), where m is the slope and b is the y-intercept.

Step 3 ：Substitute the given point into this equation to solve for b.

Step 4 ：We get m = 1.25 and b = -0.5.

Step 5 ：Now that we have the y-intercept, we can write the equation of the line in slope-intercept form.

Step 6 ：We get m = 1.25 and b = -0.5.

Step 7 ：The equation of the line is \(y = 1.25x - 0.5\).

Step 8 ：\(\boxed{y = \frac{5}{4}x - \frac{1}{2}}\) is the final answer.