INEQUALITIES 3

If 11x + 5 ≥ 16 + 7x ≥ 15x – 22; find x.

Solution

11x + 5 ≥ 16 + 7x and  16 + 7x ≥ 15x – 22

11x – 7x ≤ 16 - 5  and  15 +22 ≤ 15x - 7x [collecting like terms]

4x ≤ 11 and  37 ≤ 8x 

4x ≤ 11  and  37 ≤ 8x 

4        4          8      8

x ≤ ¹¹/4 and  ³⁷/8 ≤ x

x ≤ ¹¹/4   and  x  ≥ ³⁷/8   [ since a ≤ x = x ≥ a ]

TRY THIS………..

If 13x + 5 ≥ 16 + 7x ≥ 15x – 17; find x.