y=mx + b where b is y intercept and m is the slope. So what we need to do is to plug in the slope and the y and x values from the point. So, -4=1/2 times 8 + b. =-4=4+b. Now let's solve for be. -4-4=-8. b=-8. To verify, 4-8 is -4, so this statement is true. Now let's plug our values. y=1/2x-8. So therefore our answer will be y=1/2x-8.