2y = 48 6y = 48 y = 8 x = 2y x = 2(8) x = 16 Trouvons x (16, 8) x = 2y (4)x = 2y + 5 x + y = 17 (2y + 5

x + y = 16 y = 3x

x + (3x) = 16 4x = 16

x = 4

y = 3x y = 3(4) y = 12

Trouvons y

(4, 12)

y = 3x

x + y = 186 x = 2y

(2y) + y = 186 3y = 186

y = 62

x = 2y

x = 2(62) x = 124

Trouvons x

(124, 62)

x = 2y

2x + 2y = 48 x = 2y

2(2y) + 2y = 48 6y = 48

y = 8

x = 2y x = 2(8) x = 16

Trouvons x

(16, 8)

x = 2y

x = 2y + 5 x + y = 17

(2y + 5) + y = 17 3y + 5 = 17

3y = 12

x = 2y + 5 x = 2(4) + 5 x = 13

Trouvons y

y = 4

(13, 4)

Âge d’Élizabeth Âge d’André

X = 2y + 5

2x + 3y = 181 3x + 4y = 252

-y = -39 y = 39

2x + 3y = 181 Trouvons x

6x + 9y = 543 -6x - 8y = -504

Éliminons le x

2x + 3(39) = 181 2x + 117 = 181 2x = 64

x = 32

Le prix d’un

chandail est 32$

(32, 39)

4x + 3y = 214 5x + 2y = 208

7x = 196 x = 28

4x + 3y = 214 Trouvons y

-8x – 6y = -428 15x + 6y = 624 Éliminons le y

4(28) + 3y = 214 112 + 3y = 214 3y = 102

2y = ???

Réponse

2(34) = 68$

y = 34