Question

une espèce rare de requin est apparue en l’an −34 pour disparaître en l’an 55. pendant combien d’années cette espèce a-t-elle vécu sur terre ?

Explanation:

Step1: Understand the time period

We need to find the number of years between -34 (appearance) and 55 (disappearance). To calculate the time between two years \(a\) and \(b\) (where \(b > a\)), we use the formula \(b - a\) when dealing with years (since years are like a number line, with negative years before 0 and positive after). Here, \(a=-34\) and \(b = 55\).

Step2: Calculate the difference

The formula for the number of years lived is \(55-(-34)\). Subtracting a negative number is the same as adding its positive, so \(55 + 34=89\).

Answer:

89