Answer:
2300
Step-by-step explanation:

Domain is the numbers yo can use
we has a sqrt and a ln
we cant have any neagtive ln's or sqrts
x cannot be negative
it cannot be 0 either
domain is all numbers bigger than 0
deritivive
apply chain rule
dy/dx(f(g(x))=f'(g(x))g'(x)
and also
dy/dx (lnx)=1/x
and
dy/dx(f(x)g(x))=f'(x)g(x)+g'(x)f(x)
and from experience
dy/dx(sqrtx)=1/(2√x)
so
dy/dx(ln(2xsqrt(2+x)))=
(1/(2xsqrt(2+x))(2)(sqrt(2+x)+(x/(2sqrt(2+x))=
(3x+4)/(2x(x+2))
domain is all real numbers greater than 0
derivitive is
53.55 / 85 = 0.63
0.63 * 100 = 63
63 - 38 = 25
watch was 25 before discount
If you reverse the first two letters
Na
Fe
Hg
Sn
They are actually symbols for elements
Na - Sodium
Fe - Iron
Hg - Mercury
Sn - Tin
Since Sn is a symbol for Tin and each pair of letters imply the starting letter of the element they are symbolizing, the answer is
1) T<span />