Геометрическая прогрессия в2=9 в4=16 в6?

B2 = b1q 9 = b1q

b4 = b1q^3 16=b1q^3 разделим 2-е уравнение на 1-е, получим: q^2 = 16/9, q = + - 4/3

а) q = 4/3 9 = b1q, 9 = b1*4/3, b1 = 9:4/3 = 9 * 3/4 = 27/4, b6 = b1q^5 = 27/4 * (4/3) ^5 = 256/9

б) q = - 4/3 9 = b1q, 9 = b1 * (-4/3), b1 = 9: (-4/3) = 9 * (-3/4) = - 27/4, b6 = b1*q^5 = - 27/4 * (-4/3) ^5=256/9