Question

determine the sum of the first six terms

2-6+18;....

Answer 1

@Michy --> What's the pattern for the terms? I see that the signs seem to alternate. With three terms, it's dicey, for me at least.

Answer 2

That question came directly from the exercise, the way I did it is 2-6+18= 14, 2-6+14=10, 2-6+10=6, 2-6+6=2, 2-6+2=-2, 2-6-2=-6

=14+10+6+2+(-2)+(-6)
the constant is 4
=24

I don't know... I'm usually wrong O_o

Answer 3

I think the pattern is to multiply the previous term by -3 (negative 3) after being given the first term.

So I got the following: 3 - 6 + 18 -54 +172 - 516.

Will you check those and add them?

Post your result here.