Calcul littéral, avec les identités remarquable ou pas. 5x ² + 2 (4x + 8) (7x - 3) (7x +3) -2 (x + 5) ²

A [tex]=5x^2+ 2 (4x + 8) \\ =5x^2+8x^2+16 \\ =13x^2+16[/tex]

B [tex]=(7x-3)(7x+3)-2(x+5)^2 \\ =49x^2-9-2(x^2+10x+25) \\ =49x^2-9-2x^2-20x-50 \\ =47x^2-20x-59[/tex]

5x² + 2 (4x + 8)
= 5x²+8x+16

(7x - 3) (7x +3) -2 (x + 5)² 
= 49x²-9-2(x²+10x+25)
= 49x²-9-2x²-20x-50
= 47x²-20x-59