F3MATHS INEQUALITIES

1) 3+x ≦ 3x+1 < 10
3+x ≦ 3x+1 and 3x+1 < 10
2≦2x and 3x< 9
1≦x and x< 9

so, 1≦x< 9

2) x/4 + 7 ≦ 3x/5 AND 6x + 4 < 27
7 ≦ (3/5 - 1/4)x and 6x< 23
7 ≦ x and x < 23/6 (!!!)
there is no solution.

3) 6x + 4 > 16 or 3x - 5 < 1
6x > 12 or 3x < 6
x > 2 or x < 2