What is the 8th term of the geometric sequence 4, −20, 100, …? −312,500 −12,500 62,500 1,562,500?

Let us first check the common ratio for this Geometric series .

-20/ 4= -5

100/-20 = -5

Ratio of any term with it's previous term is -5 so that is the common ratio here .

here first term a= 4 and common ratio r= -5

we know nth term of geometric series is an= a r^(n-1)

let us plug n= 8 a= 4 and r= -5 a8 = 4 ( -5)^(8-1)

a8 = 4 (-78125) = -312500

Answer : -312500

1,589.63 in.^3

step-by-step explanation:

i hope this you : d

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116