Sagot :
Bonjour
A= ( 7x + 4 )² = 49x² + 56x +16
B= ( 8 - 9x )² = 64 - 144x +81x²
C= ( 9 + 6x ) ( 9 - 6x ) = 81 - 36x²
D= ( x - 3 ) ( 12 - 5x ) = 12x -5x² - 36 + 15x = -5x² +27x -36
E= 5x - 2 ( 11x + 13 ) - ( 30 + x ) ² = 5x - 22x - 26 - (900 + 60x + x²)
= 5x - 22x - 26 - 900 -60x - x²
= -x² - 82x - 926
A= ( 7x + 4 )² = 49x² + 56x +16
B= ( 8 - 9x )² = 64 - 144x +81x²
C= ( 9 + 6x ) ( 9 - 6x ) = 81 - 36x²
D= ( x - 3 ) ( 12 - 5x ) = 12x -5x² - 36 + 15x = -5x² +27x -36
E= 5x - 2 ( 11x + 13 ) - ( 30 + x ) ² = 5x - 22x - 26 - (900 + 60x + x²)
= 5x - 22x - 26 - 900 -60x - x²
= -x² - 82x - 926