Résoudre ce système : 5x - 3y = -1 4x + 7y= 16

Tu fais la résolution par substitution ou par combinaison ?

5x - 3y = -1
4x + 7y = 16

5x - 3y = -1
4x = 16 - 7y

5x - 3y = -1
x = 16/4 - 7y/4

5x - 3y = -1
x = 4 - 7y/4

5 (4 - 7y/4) - 3y = -1
x = 4 - 7y/4

20 - 35y/4 - 3y = -1
x = 4 - 7y/4

-35y/4 - 3y = -1 - 20
x = 4 - 7y/4

-35y/4 - 12y/4 = -21
x = 4 - 7y/4

-47y/4 = -21
x = 4 - 7y/4

-47y = -21×4
x = 4 - 7y/4

y = -84/-47
x = 4 - 7y/4

y = 84/47
x = 4 - (7×84)/47/4

y = 84/47
x = 4 - 588/47 × 1/4

y = 84/47
x = 4 - 588/(47×4)

y = 84/47
x = 4 - 588/188

y = 84/47
x = 4 - 147/47

y = 84/47
x = 4×47/47 - 147/47

y = 84/47
x = 188/47 - 147/47

y = 84/47
x = 41/47