Bonsoir voilà la réponse :
a) 4x+2-4(1-x) = 2x+1
4x+2-4*1(-4)*(-x) = 2x+1
4x+2-4+4x-2x-1 = 0
4x+4x-2x+2-4-1 = 0
6x-3 = 0
6x = 3
x = 3/6 = 1/2
b) 7(-x+3)+2(x-3) = 5(3-x)
7*(-x)+7*3+2*x+2*(-3) = 5*3+5*(-x)
-7x+21+2x-6 = 15-5x
-7x+21+2x-6-15+5x = 0
-7x+2x+5x+21-6-15 = 0
0x+0 = 0
x = 0
c) 2-1/2(x+1)+3/4(3x-2) = 14/2
2-1/2*x-1/2*1+3/4*3x+3/4*(-2) = 7
2-x/2-1/2+9x/4-6/4-7 = 0
-x/2+9x/4+2-1/2-3/2-7 = 0
-2x/4+9x/4+4/2-1/2-3/2-14/2 = 0
(-2x+9x)/4+(4-1-3-14)/2 = 0
7x/2+(-14)/2 = 0
(7x-14)/2 = 0
7x-14 = 0*2
7x-14 = 0
7x = 14
x = 14/7 = 2
Voilà j'espère avoir pu t'aider ^^
