A) A = 3+1 5+ 5+1 7 + 71+ 9 + ...+ 971+ 99 = 12( 5− 3+ 7− 5+ 9− 7+ ......

b) B = 35 + 335 + 3335 + ... +

_ˆ

so′

=

99

3

=33 +2 +333+2 +3333+2+...+ 333....33+2

= 2.99 + ( 33+333+3333+...+333...33)

= 198 +

( 99+999+9999+...+999...99)

198 +

( 10

²

-1 +10

³

- 1+10

⁴

- 1+ ....+10

¹⁰⁰

– 1) = 198 – 33 +

B =

¹⁰¹

²

+165