Bonsoir,
√16 = 4 ( 4*4 = 16)
√9 = 3 ( 3*3 = 9)
√25 = 5 ( 5*5 = 25)
Donc √16 + √9 - √25 <=> 4 + 3 - 5 = 7 - 5 = 2
* = multiplication
Bonne soirée