The equation for the line given is y = 4/5x - 3. This equation is in <em>slope-intercept form</em>, which always looks like y = mx + b. The "m" in that is the slope, so we can use this information to find the slope in the equation.
It looks like 4/5 is before the x in y = 4/5x - 3, and so 4/5 has to be our "m," and thus our slope. So, that's the answer. Hopefully that's helpful! If have any more questions, let me know. :)