bjr
P = x*x + x*2 + 12 *x + 12*2
P = x² + 14x + 24
comme a² - b² = (a+b) (a-b)
on aura
Q = (x+7)² - 5² = (x+7+5) (x+7-5) = (x+12) (x+2)
triangle rectangle en A => hypoténuse = BC
pythagore => BC² = AB² + AC²
=> AC² = BC² - AB² = (x+7)² - 5² = x² + 14x + 49 - 25 = x² + 14x + 24
