Y = -3/4x + 5.....the slope here is -3/4...but for a perpendicular line, we need the negative reciprocal slope. All that means is " flip " the slope and change the sign. So the slope we need is 4/3 (see how I flipped the slope and changed the sign)
now we use y = mx + b slope(m) = 4/3 (3,-1)...x = 3 and y = -1 now we sub and solve for b, the y int -1 = 4/3(3) + b -1 = 4 + b -1 - 4 = b -5 = b