For the geometric sequence, it has two forms of formula


We are interested in the recursive formula now


 {-80, 20, -5, ...}

The common ratio is (20/-80)=(-5/20)=-1/4=-0.25

So our recursive formula would be $a_n=a_{n-1}*(-0.25)=a_{n-1}*(- \frac{1}{4} )$

I hope that helps!

3 0

2 years ago

Solve 5c − c + 10 = 34. −6 6 11 −11

natima [27]

Subtract 10 and collect terms to get the variable term by itself on the left.

... 4c = 24

Divide by the coefficient of the variable, 4.

... c = 6

The appropriate choice is the second one:

... 6

_____

You don't actually have to sove the equation to find the right answer. You just need to see which answer works.

-6: 5(-6) -(-6) +10 = -14 ≠ 34

6: 5(6) -(6) +10 = 34 . . . . . . . this answer works (you can stop here)

11: 5(11) -(11) +10 = 54 ≠ 34

-11: 5(-11) -(-11) +10 = -34 ≠ 34

7 0

2 years ago