Réponse:
Bonjour/ bonsoir,
.A=(x+5)²= x²+2×x×5+5²
= x²+10x+25
.B=(3-x)²=3²-2×3×x+x²
=9-6x+x²
.C=(x+5)(x-5)=(x)²-(5)²
=x²-25
.D=(2x+1)²=(2x)²+2×2x×1+1²
=4x²+4x+1
.E=(1-3x)(1+3x)=(1)²-(3x)²
=1-9x²
.F=(5-5x)²=5²-2×5×5x+(5x)²
=25-50x+25x²
.G=(3x-1/3)²=(3x)²-2×3x×1/3+(1/3)²
=9x²-2x+1²/3²
=9x²-2x+1/9
.H=(4x-1)(4x+1)-5x(1-3x)
=(4x)²-(1)²-5x-5x×(-3x)
=16x²-1-5x+15x²
=31x²-5x-1
Voila, j'espère que tu as compris☻☺︎.
