She earns ($9.70x40) for a 40 hour week=$388
She earned $489.85-$388 extra= $101.85
She gets paid $9.7x1.5 for every extra hour=$14.55
She worked $101.85/$14.55 hours extra=7hours
She worked 7+40 hours that week=47 hours
Changing the x from positive to negative, reflects the graph over the Y-Axis.
Adding 7 to X shifts the graph horizontally 7 units to the right.
The formula of a slope:

We have the points (-4, -3) and (-3, s) and the slope m = 3. Substitute: