3x-x^2>0
⚠ 3x is read as the product 3*x: for a power, write 3^x
Let's solve in ℝ: 3x -x2 > 0
You can factor: 3x -x2 into: x·(3 -x)
Solution found: x > 0
Let's solve in ℝ: 3 -x > 0
3 > x
Solution found: x < 3
Let's aggregate the different solutions to find the overall solution:
x-∞ 0 3 +∞
x-×++
3 -x++×-
3x -x2-×+×-
▶Solution obtained: x ∈ (0, 3)