As we know the formula to calculate the slope is m = y2 - y1 divided by x2 - x1.
Where m is the slope. y2 is the second y co ordinate. y1 is the first y co ordinate. x2 is the second x co ordinate. x1 is the first x co ordinate.
So to calculate we can write it out as -7 = v - (-5) / 5 - 7, which further becomes -14 = v + 5 and v comes out to be -19.