First observe that if
,

Let
and
. It follows that

Now let
, so
. Solving for
,

which means

Now solve for
.

(note that we assume
)

(we omit
since
is not true)
≥ can be written in both the circles
I think is this hopefully this helps
Seeing as there are 1582 sets of 100 people (158200 ÷ 100) multiplying 42 by 1582 should get you the answer. 1582 × 42 = 66444. 66444 people voted in that city.
The Square Root Of 8100 Is 90. That Will Be The Only Square Root Because The Square Root Of 90 Is A Decimal So You Would Stop There.