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bonjour
xx = x²
xxx = x³
xxxx = x⁴
4 + 20xxxx - xx4xxx3 = 4 + 20 x⁴ - x² * 4 * x³ * 3
= 4 + 20 x⁴ - 4 * 3 * x² * x³
= 4 + 20x⁴ - 12 x²⁺³
= 4 + 20x⁴ - 12x⁵
bonjour
xx = x²
xxx = x³
xxxx = x⁴
4 + 20xxxx - xx4xxx3 = 4 + 20 x⁴ - x² * 4 * x³ * 3
= 4 + 20 x⁴ - 4 * 3 * x² * x³
= 4 + 20x⁴ - 12 x²⁺³
= 4 + 20x⁴ - 12x⁵