For the following geometric sequence find the explicit formula: {-1, 3, -9, ...}. an = -3 · an - 1 where a1 = -1 an = (-3) n - 1 an = -3 · an - 1 where a1 = 1 an = -1 · (-3) n - 1

= - 1

Step-by-step explanation:

The n th term ( explicit formula ) for a geometric sequence is

= a

where a is the first term and r the common ratio

Here a = - 1 and r = - 9 ÷ 3 = 3 ÷ - 1 = - 3, thus

= - 1 with a₁ = - 1

y=3x+4

step-by-step explanation:

given the points a(0,4) and b(-4, -8)

eqn of line ab: (y-4)/(x-0)=(-8-4)/(-4-0)

(y-4)/x=-12/-4=3

y=3x+4