The line 2y+7x=5 and 4x+dy+3=0 are perpendicular to each other. Find the value of the constant 'd'. (5marks)

Answer 1

7X + 2Y = 5 and 4X + dY = 0
m1 = -A/B = -7/2.
m2 = 2/7 = neg. reciprocal of m1.
m2 = -A/B.
2/7 = --4/d
2d = -28
d = -14.