x(x-5)>= 0
Let's solve in ℝ: x·(x -5) ≥ 0
We study the sign of each factor of the product
⇥The expression x is zero at x = 0, it is negative before and positive after
⇥The expression x -5 is zero at x = 5, it is negative before and positive after
Let's draw up the sign table:
x-∞ 0 5 +∞
x-0++
x -5--0+
x·(x -5)+0-0+
▶Solution found: x ∈ (-∞, 0] ∪ [5, +∞)