Answer: Choice C
y = (1/2)x - 9/2
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Step-by-step explanation:
The equation y+2x = 1 solves to y = -2x+1 after subtracting 2x from both sides.
That second equation is in the form y = mx+b
The slope in this case is m = -2. Flip the fraction and flip the sign to get 1/2.
The original slope is -2 and the perpendicular slope is 1/2. The two slopes multiply to -1.
We'll use this new slope as the m value, along with the coordinates (7,-1) to solve for b like so:
y = mx+b
-1 = (1/2)*7+b
-1 = 3.5+b
-1-3.5 = b
-4.5 = b
b = -4.5
b = -9/2
Since m = 1/2 and b = -9/2, this means we go from y = mx+b to y = (1/2)x-9/2 which is choice C
The graph is below.