5 × [ 5 + 5 × ( 5³ - 5³ : 5³ ) ] + 3 × 5³ = 3 500
= 5 × [ 5 + 5 × ( 125 - 1 ) ] + 3 × 125 =
= 5 × ( 5 + 5 × 124 ) + 375
= 5 × ( 5 + 620 ) + 375 =
= 5 × 625 + 375 =
= 3 125 + 375 =
= 3 500
