4x-19 = x-10 <=> 3x-19 = -10
<=> 3x = 9
<=> x = 9/3 = 3
3x-14 = 4x+17 <=> -x-14 = 17
<=> -x = 31
<=> x = -31
"5x+12=5x-15"
T'es sûr d'avoir bien écrit ? J'ai tapé l'équation dans ma Casio 35+ et elle affiche "Résolution impossible".
2(x-5)=3(-x+2) <=> 2x-10 = -3x+6
<=> 5x-10 = 6
<=> 5x = 16
<=> x = 16/5
-3(-a+3)=5(3-a)+2 <=> 3a-9 = -5a +17
<=> 8a = 26
<=> a = 26/8 = 13/4
m-(5-3m)=3m+4 <=> 4m-5 = 3m+4
<=> m-5 = 4
<=> m = 9