Răspuns :
= 5^1000( 1 + 5 + 5^2) = 5^1000 x ( 6 + 25) = 5^1000 x 31 = > divizibil cu 31
5¹⁰⁰⁰+5¹⁰⁰¹+5¹⁰⁰² = 5¹⁰⁰⁰(1+5¹+5²) = 5¹⁰⁰⁰ * 31 = M₃₁ [tex]\vdots\;31[\tex]