Sagot :

Bonjour la calculatrice c'est facile.
[tex]2x-6x=12+ \frac{1}{4} x<=>- \frac{16}{4}x - \frac{1}{4} x=12<=>- \frac{17}{4} x=12<=>x=51[/tex]

[tex]5x+3=7x+8<=>-2x=5<=>x=10[/tex]

[tex]7x+6=-7x+8<=>14x=2<=>x= \frac{1}{7}[/tex]

[tex] \frac{12}{3}x+ \frac{1}{3} = \frac{2}{6} +1<=> \frac{12}{3} x=1<=>x=-4[/tex]