What is the sum of the geometric sequence 3,12, if there are 8 terms? a) 21,845 b)43,690 c)65,535 d)87,380

  C)  65,535

Step-by-step explanation:

You can add up the 8 terms ...

  3, 12, 48, 192, 768, 3072, 12288, 49152

to find their sum is 65535.

Estimating

Knowing the last term (49152) allows you to make the correct choice, since the sum will be more than that and less than double that.

Using the formula

You know the formula for the sum of a geometric sequence is ...

  S = a1(r^n -1)/(r -1)

where a1 is the first term (3), r is the common ratio (4), and n is the number of terms (8).

Filling in the values, you find the sum is ...

  S = 3(4^8 -1)/(4-1) = 4^8 -1 = 65535

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations:

step-by-step explanation:

3024 rhe base is what up in worry about