y = x/2 + 3......x/2 is the same as 1/2x....so u have a slope of 1/2.
A perpendicular line will have a negative reciprocal slope. To find the negative reciprocal, flip the slope and change the sign. So we have 1/2....and we flip it making it 2/1....and we change the sign making it -2/1 or just -2. So ur perpendicular line will have a slope of -2.
y = mx + b
slope(m) = -2
(1,8)...x = 1 and y = 8
now we sub and find b, the y int
8 = -2(1) + b
8 = -2 + b
8 + 2 = b
10 = b
so ur perpendicular equation is : y = -2x + 10 <==
