Since you have the slope, you can start your equation with y= -8/7x +b. To find b, plug the X value for the point you were given in for the X (-8/7•4) you get -32/7 or -4.57. Then you take the given Y value(4) and subtract the number you just found (4-(-4.57)). You get 8.57. That means your equation is Y= -8/7 + 8.57
