Bonsoir.
Equation 1 :
x - 1/12 = 1/4
⇔ x = 1/4 + 1/12
⇔ x = 3/12 + 1/12
⇔ x = 4/12
⇔ x = 1/3
Equation 2 :
5 × (x - 2) + 2 × (1 - 3x) = 7x + 12
⇔ 5x - 10 + 2 - 6x = 7x + 12
⇔ 5x - 6x - 7x = 12 + 10 - 2
⇔ - 8x = 20
⇔ x = 20/(- 8)
⇔ x = - 5/2
Bonne soirée !
