Ineed ! solve for x. similar polygon practice

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?

When is g(x) = 0 for the function g(x) = 5.23x + 4?

What is the sum of the geometric series in which a1 = 7, r = 3, and an = 1,701? hint: cap s sub n equals start fraction a sub one left parenthesis one minus r to the power of n end power right parenthesis over one minus r end fraction comma r ≠ 1, where a1 is the first term and r is the common ratio