-5, 20, -80, 320, ... is a geometric
sequence.
What is the explicit rule

Multiplied by -4

Step-by-step explanation:

-5 (-4) = 20

20 (-4) = -80

-80 (-4) = 320

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