x - 2y = 10
-2y = -x + 10
y = 1/2x - 5...slope here is 1/2. A perpendicular line will have a negative reciprocal slope. All that means is flip the slope and change the sign. So our perpendicular slope is -2 (see how I flipped 1/2 over...making it 2/1...and changed the sign..making it -2)
y = mx + b
slope(m) = -2
(2,6)...x = 2 and y = 6
now we sub and find b, the y int
6 = 2(-2) + b
6 = -4 + b
6 + 4 = b
10 = b
so ur perpendicular equation is : y = -2x + 10 <==