Each one is multiplied by -2...
PROOF
-5 * 10 = -20
-20 * -2 = 40
And so on.
So we need two more numbers so do 40 * -2...
40 * -2 = -80
And then...
-80 * -2 = 160
So the first 6 numbers are...
-5, 10, -20, 40, -80, 160.
We need to find the SUM, which is all the numbers added together.
-5 + 10 - 20 + 40 - 80 + 160 = 105
105 is your answer.
