Sagot :
Bonjour,
(a + b)⁴ = ((a+b)²)² = (a²+2ab+b²)²
= (a²+2ab+b²)(a²+2ab+b²)
= a⁴+2a³b+a²b²+2a³b+4a²b²+2ab³+b²a²+2ab³+b⁴
= a⁴+4a³b+6a²b²+4ab³+b⁴
= a⁴ + b⁴ + 4a³b + 4ab³ + 6a²b²
(a + b)⁴ = ((a+b)²)² = (a²+2ab+b²)²
= (a²+2ab+b²)(a²+2ab+b²)
= a⁴+2a³b+a²b²+2a³b+4a²b²+2ab³+b²a²+2ab³+b⁴
= a⁴+4a³b+6a²b²+4ab³+b⁴
= a⁴ + b⁴ + 4a³b + 4ab³ + 6a²b²
= (a²+2ab+b²)(a²+2ab+b²)
= a⁴+2a³b+a²b²+2a³b+4a²b²+2ab³+b²a²+2ab³+b⁴
= a⁴+4a³b+6a²b²+4ab³+b⁴
= a⁴ + b⁴ + 4a³b + 4ab³ + 6a²b²
