Question 7 Un contrôleur aérien observe 2 avions. Il constate qu'au moment où l'avion A amorce sa
descente pour atterrir, l'avion B quitte le sol. Au moment où l'avion A amorce sa descente, il
vole à une altitude de 920 m. Après 20 secondes, l'avion
A est a 820 m et l'avion B est à 100 m.
Le schéma n'est pas à l'échelle.
À quel moment les deux avions se croiseront ils ?
L'altitude (m)
L'altitude des avions selon le temps
Avion B
820
Avion A
100
Temps(s)
20

the answer is d

step-by-step explanation:

region b will make the inequalities y < 2x + 1 and y > -x - 2 true ⇒ answer a

step-by-step explanation:

* lets study the graph and the inequality to solve the question

- the inequality y > -x - 2

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = -2 that means the line intersect the y-axis at point (0 , -2)

∵ the sign of the inequality is >

∴ we shad the part over the line

  region a and b

- the inequality y < 2x + 1

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = 1 that means the line intersect the y-axis at point (0 , 1)

∵ the sign of the inequality is <

∴ we shad the part under the line

  region b and c

∵ the common region between the two lines is region b

∴ region b will make the inequalities y < 2x + 1 and y > -x - 2 true

time is equal to distance over rate so

t = d/r

need a little bit more information for the second question.