(b) 3x – 2y + 5 Let the equation of the L be y = mx + c Since O′ (–2, 6) is the image of the point O (4, 2) in line L = 0, the mid-point of OO′, i.e., \(\bigg(rac{-2+4}{2},rac{6+2}{2}\bigg)\), i.e.,(1, 4) will lie on the given line. Also, L ⊥ OO′, so Slope of L x Slope of OO′ = –1⇒ m x \(\bigg(rac{6-2}{-2-4}\bigg)\)= -1 ⇒ m = \(rac{-1}{rac{-2}{3}}\) = \(rac{3}{2}\)∴ Equation of L is y = \(rac{3}{2}\,x+c\)∵ It passes through (1, 4)4 = \(rac{3}{2}\) x 1 + c ⇒ c = 4 - \(rac{3}{2}\) = \(rac{5}{2}.\)∴ Required equation is y = \(rac{3}{2}x\) + \(rac{5}{2}\)⇒ 3x – 2y + 5 = 0 ∴ L = 3x – 2y + 5.