Question

What is the equation of the line perpendicular to the line y =4/9 x – 2 that passes through the point (4,3)?

Answer 1

Line y = 4/9 x - 2 has a slope of 4/9.
For perpendicular lines, the ploduct of the two slopes is -1. Thus the slope of the required line is -1/(4/9) = -9/4

Equation of a line is given by y - y1 = m(x - x1)
y - 3 = -9/4(x - 4)
y - 3 = -9/4 x + 9
y = -9/4 x + 9 + 3
y = -9/4 x + 12.

Answer 2

An815
Helping Hand line through point (a,b) with slope is given by
y-b=m(x-a)
slope of -9/4 is perpendicular to slope of 4/9, as y=4/9x-2 has slope 4/9. Our point is (4,3) therefore.
y-3=-9/4*(x-4)
y-3=-9/4x+9
y=-9/4x+9+3
y=-9/4x+12