Respuesta :
-2n(5 + n - 8 - 3n) = -2n(-3 - 2n) = 6n + 4n²
n = 3, subtitute
6 · 3 + 4 · 3² = 18 + 4 · 9 = 18 + 36 = 54
n = 3, subtitute
6 · 3 + 4 · 3² = 18 + 4 · 9 = 18 + 36 = 54
-2×3 (5+3 - 8 - 3×3)
↓ ↓ ↓
-6 ( 8 - 8 - 9)
↓
0
-6 (-9)
↓
54: answer
↓ ↓ ↓
-6 ( 8 - 8 - 9)
↓
0
-6 (-9)
↓
54: answer