Answer:
The correct answer is D.
Step-by-step explanation:
We need to find the slope of 3x-4y=20.
3x-4y=20
-4y=-3x+20
y=(3/4)-5
Perpendicular lines will always have negative reciprocals, so we need to find a line that has a slope of -4/3 ( flip the numbers and add a negative) and passes through the points (1,-1). We can use the point-slope formula.
y-y1=m(x-x1), where m is slope.
Substitute values.
y-(-1)=(-4/3)(x-1)
Simplify
y+1=(-4/3)x+(4/3)
Multiply both sides by 3
3y+3=-4x+4
Add 4x
3y+4x+3=4
Subtract 3
3y+4x=1
The correct answer is D
