bonjour,
soit x le coté adjacent inconnu
(x+2) = l'hypoténuse
(x+2)² =x²+5²
x²+4x+4 = x²+25
x²+4x+4-x² = 25
4x = 25-4
x = 5,25
hypoténuse = 7,25cm
cotés adjacents = 5,25 et 5cm
7,25² = 52,5625
5,25²+5² =52,5625
exo 2 :
A rectangle = x(x/2+1) = x²/2 - 1 = (x²-2)/2
A triangle = [(x+4)(x/2 -1)]/2 = [(x²/2+4x/2-x-4]/2 = [(x²/2 + x-4]/2
(x²+2x-8)/2]/2 = (x²+2x-8)/4
résous (x²-2)/2<(x²+2x-8)/4
