Sagot :
Bonjour,
Développer :
= (-3t+1)²+(5t-3)(-t+4)
= (1-3t)²+(5t-3)(-t+4)
= (1-3t)²-5t²+20t+3t-12
↳ Identité remarquable : (a-b)² = a²-2ab+b².
= 1-6t+9t²-5t²+20t+3t-12
= -11-6t+9t²-5t²+20t+3t
= -11+17t+9t²-5t²
= -11+17t+4t²
↳ Loi commutative.
= 4t²+17t-11
Bonne journée.