Repede va rog doar cele inconjurate

a) ( - 1 / 5 )⁶ x ( - 1 / 5 ) ⁴ = ( - 1 / 5 ) ⁽ ⁶ ⁺ ⁴ ⁾ = ( - 1 / 5 ) ¹⁰ Adevarat
b) ( - 1 / 9 )² : ( - 1 / 3 )² = ( - 1 / 3 )² Adevarat
= ( - 1 / 3² )² : ( - 1 / 3 )² =
= ( - 1 / 3 ) ⁴ : ( - 1 / 3 ) ² =
= ( - 1 / 3 ) ⁽ ⁴ ⁻ ² ⁾ =
= ( - 1 / 3 ) ²