Quis5! + 7! – 2! =​

5!+7!-2!

=(5×4×3×2×1)+(7×6×5×4×3×2×1)-(2×1)

=(20×3×2×1)+(42×5×4×3×2×1)-2

=(60×2×1)+(210×4×3×2×1)-2

=120+(840×3×2×1)-2

=120+(2.520×2×1)-2

=120+5.040-2

=5.160-2

=5.158

• 5! + 7! – 2!

= ( 5 × 4 × 3 × 2 ) + ( 7 × 6 × 5 × 4 × 3 × 2 ) – 2

= ( 20 × 3 × 2 ) + ( 42 × 5 × 4 × 3 × 2 ) – 2

= ( 60 × 2 ) + ( 210 × 4 × 3 × 2 ) – 2

= 120 + ( 840 × 3 × 2 ) – 2

= 120 + ( 2.520 × 2 ) – 2

= 120 + 5.040 – 2

= 5.160 – 2

= 5.158