90+(2x+15)+x=180
90+2x+15+x=180
105+3x=180
3x=75
x=75/3
x=25degree
Sub x=3 into ((x^2)-x)^2 - (x^2 - x) = 30. So the answer is A.
Given:
and
where
.
To find:
The explicit formula for the given recursive formula.
Solution:
We know that recursive formula of an AP is:

Where, d is the common difference.
We have,

Here, d=9.
The first term of the AP is
.
The explicit formula for an AP is:

Substituting
and
, we get



Therefore, the required explicit formula for the given sequence is
.
(x+17)(x+17)=
I believe this is what you are looking for friend