x<5,4

It looks like you wrote x<5,4 with a comma as the decimal separator. I’ll interpret it as x < 5.4.

• Real solution set: all real numbers less than 5.4.
• Interval notation: (-∞, 5.4)
• Graph on a number line: open circle at x = 5.4 and shade to the left.
• If x is restricted to integers: x ∈ {..., 2, 3, 4, 5} (i.e., x ≤ 5).

If you meant something else (e.g., a system of inequalities or a different decimal format), please share the full problem.