Resposta :
a) (x-1)/3 - (x-2)/2 ≤ 2
mmc de 3 e 2 = 6, portanto
2(x-1) - 3(x-2) ≤ 2
2x - 2 - 3x + 6 ≤ 12
-x +4 ≤ 12
-x ≤ 8
x ≥ -8
{x pertence a R| x ≥ -8}
b) 2(3 - x)/5 + x/2 ≥ 1/4 + 2(x - 1)/3
mmc de 5,2,4,3 = 60, portanto
12.2(3-x) + 30.x ≥ 15 + 20.2(x-1)
72 - 24x + 30x ≥ 15 + 40x - 40
-24x + 30x - 40x ≥ 15 -72 -40
-34x ≥ -97
x≤ 97/34
{x pertence a R| x ≤ 97/34}
c)3x - 1/4 - x - 3/2 ≥ x+ 7/4
mmc de 2,4 = 4, portanto
4.3x - 1 - 4x - 2.3 ≥ 4x + 7
12x - 4x -4x - 6 ≥ 7 + 1 + 6
12x ≥ 14
x ≥ 14/12
x ≥ 7/6
{x pertence a R| x ≥ 7/6}