Find the sum of the geometric sequence -3,15,-75,375,... when there are 7 terms and select the correct answer below.

-39,063

Step-by-step explanation:

In this geometric, sequence, you are multiplying by -5. So, we can continue the sequence by mulitplying 375(your last value) by -5 and so on, until we have 7 total terms.

Now we add the terms together:

-3+15+-75+375+-1875+9375+-46875

=-3+15-75+375-1875+9375-46875

=-39063

Hope this helps :)

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0