None? Unless the second option is supposed to be 10^2 or the fourth option is 50 x 2.
X=f
x×1+1-2+3=3234557901028292
He will need about 3.14 or pi since circumference= pi*d
Match bases
if a^x=b^x where x=x then a=b
hmmm
1/8=8^-1=(2^3)^-1=2^-3
so
2^n=2^-3
n=-3
