7800 - 4 × 8 + 21 - 3 × 7 = 7768
Verificare:
7800 - 4 × 8 + 21 - 3 × 7 =
= 7800 - 32 + 21 - 21 =
= 7768 + 21 - 21 =
= 7789 - 21 =
= 7768
========================
5 × (5 × 5 +5) - 5 + 5 : 5 = 146
Verificare:
5 × (5 × 5 +5) - 5 + 5 : 5 =
= 5 × (25 +5) - 5 + 1 =
= 5 × 30 - 5 + 1 =
= 150 - 5 + 1 =
= 145 + 1 =
= 146
.
.