9)
0.1 = 10^-1
0.01 = 10^-2
0.001 = 10^-3
0.000001 = 10^-6
Each time the point goes one number backward, it make 10^-1. This means that if the point goes 2 numbers backward, it's *10^-2, etc...
10) an atom is 0.0000000001 meter. You can see that from 1, the point has went 10 times backward. So 0.0000000001 is 10^-10 meters.
11) Multiplying exponents that have the same base is equal to that same base with the add of the exponents:
2^(-3) * 2^(-4) = 2^(-3-4) = 2^(-7)
s^(-5) * s^(-2) = s^(-5-2) = s^(-7)
y^(-1) * y^4 = y^(-1+4) = y^3
3a * a^-3 = 3a^(1-3) = 3a^(-2)
Dividing is exponents with the same base is equal to the same base with the subtraction of the exponents:
3^(-1) / 3^(-5) = 3^(-1-(-5)) = 3^(-1+5) = 3^4
a^(-4) / a^(-6) = a^(-4+6) = a^2
y^(-6) / y^(-10) = y(-6+10) = y^4
z^(-4) / z^(-8) = z^(-4+8) = z^4
Hope this Helps! :)