bonsoir,
GD = x donc EB = 2 x
a ) A ( x) = ( 16 - 2 x ) ( 8 - x )
b ) A ( x) = 128 - 16 x - 16 x + 2 x²
A ( x) = 2 x² - 32 x + 128
c ) 2 ( 8 - x ) ² = 2 ( 64 - 16 x + x²) = 128 - 32 x + 2 x²
d) quand x = 4
A (x) = 2 * 4² - 32 * 4 + 128 = 32 - 128 + 128 = 32