6)a) We can say, 10^p = x
b) 10^p multiplied by 10 = 10x
c) (10^p)^2/10^3 =x^2/1000
d) 10^2/10^p = 100/x
7)a) Clearly, 10^a = x, 10^b = y, 10^(a+b) = z
z = 10^(a+b)
Or, z = 10^a multiplied by 10^b = x multiplied by y = xy
I hope the remaining now you can do yourself easily now :-)