7 ≤

(3x+11)

2

≤ 11
Multiplying each side by 2, we get
7 × 2 ≤

(3x+11)

2

× 2 ≤ 11 × 2 or 14 ≤ 3x + 11 ≤ 22
Subtracting 11, we get
14 – 11 ≤ 3x + 11 – 11 ≤ 22 – 11 or 3 ≤ 3x ≤ 11
Dividing by 3, 1 ≤ x ≤

11

3

i.e., x is greater than or equal to 1 and less than or equal to

11

3

or x ∊ [1,

11

3

]