y = 1/3x - 7...slope here is 1/3...a perpendicular line will have a negative reciprocal slope. Allll that means is " flip " the slope and change the sign. So the slope we need is -3/1 or just -3....see how I flipped the slope and changed the sign.
y = mx + b
slope(m) = -3
(4,-2)...x = 4 and y = -2
now we sub and find b, the y int
-2 = -3(4) + b
-2 = -12 + b
-2 + 12 = b
10 = b
so ur perpendicular line is : y = -3x + 10
