Question

How to solve:
2x-4(x+7)≤13

Answer 1

2x - 4(x + 7) ≤ 13
2x - 4x - 28 ≤ 13
-2x ≤ 41
x ≥ 41/(-2)
x ≥ -20.5
The inequality sign is changed once you divide with a negative sign. Trust me.

Answer 2

2x-4(x+7)<=13
⇒ 2x-4x-28 <=13
⇒ -2x <= 13+28
⇒ -2x <= 41
⇒ x >= 41/(-2)
⇒ x >= -20.5

The final answer is x ≥ -20.5~