Алгебра 9 класс учебник Макарычев, Миндюк ответы – номер 673

b₁ = 135; b₉ = 5/3

b_n = b₁q^{n - 1}

b₉ = b₁q⁸

5/3 = 135 · q⁸

q⁸ = 5/3 : 135 = 5/3 · 1/135 = 1/81

q₁ = $$\sqrt{\frac{1}{3}}$$ = $$\frac{1}{\sqrt{3}}$$ = –$$\frac{\sqrt{3}}{3}$$

b₂ = b₁q = 135 · $$\frac{\sqrt{3}}{3}$$ = 45$$\sqrt{3}$$ или b₂ = b₁q = 135 · –$$\frac{\sqrt{3}}{3}$$ = –45$$\sqrt{3}$$

b₃ = b₂q = –45$$\sqrt{3}$$ · $$\frac{\sqrt{3}}{3}$$ = –45 или b₃ = b₂q = –45$$\sqrt{3}$$ · (–$$\frac{\sqrt{3}}{3}$$) = 45

b₄ = b₃q = –45$$\sqrt{3}$$ · (–$$\frac{\sqrt{3}}{3}$$) = 15$$\sqrt{3}$$ или b₄ = b₃q = –45$$\sqrt{3}$$ · $$\frac{\sqrt{3}}{3}$$ = –15$$\sqrt{3}$$

b₅ = b₄q = –15$$\sqrt{3}$$ · $$\frac{\sqrt{3}}{3}$$ = –15 или b₅ = b₄q = –15$$\sqrt{3}$$ · (–$$\frac{\sqrt{3}}{3}$$) = 15

b₆ = b₅q = –15$$\sqrt{3}$$ · $$\frac{\sqrt{3}}{3}$$ = –5$$\sqrt{3}$$ или b₆ = b₅q = –15$$\sqrt{3}$$ · (–$$\frac{\sqrt{3}}{3}$$) = 5$$\sqrt{3}$$

b₇ = b₆q = –5$$\sqrt{3}$$ · $$\frac{\sqrt{3}}{3}$$ = –5 или b₇ = b₆q = –5$$\sqrt{3}$$ · (–$$\frac{\sqrt{3}}{3}$$) = 5

b₈ = b₇q = –5 · $$\frac{\sqrt{3}}{3}$$ = $$\frac{-5\sqrt{3}}{3}$$ или b₈ = b₇q = –5 · (–$$\frac{\sqrt{3}}{3}$$) = $$\frac{5\sqrt{3}}{3}$$