If S1 = 9, S2 = 99, S3 = 999, S4 = 9999, ...... what is S20-S19?
A.( 3^2)(10^19)
B.( 3)(10^20)
C. (3)^3 (10^19)
D. (3) ( 10^19)
E. ( 3)^3 ( 10^18)
A.( 3^2)(10^19)
B.( 3)(10^20)
C. (3)^3 (10^19)
D. (3) ( 10^19)
E. ( 3)^3 ( 10^18)
