Answer:
So the slope in this case is m = -2. Using point (0, 7) and m =-2 with point-slope we have y - 7 = -2(x-0) => y = -2x +7. Then we realize (0,7) actually is the y-intercept. We could have gone directly to y = -2x + 7. If we use (3,1) and m = -2 we get y-1=-2(x-3) => y -1 = -2x+6 => y = -2x+7. Another way to find y-intercept is to use y = mx +b directly. If we use the point (3,1) that means when x=3, y = 1. So 1=-2(3) + b => 1=-6+b => b = 7. So, y = -2x+7. Same result in all cases. I like to use point-slope. Others prefer to use y = mx+b, substituting for x, y, and m to solve for b.
Step-by-step explanation:
