domain of f(x)=(sqrt(x+5))/(x-8)
We save the definition: f(x) = x + 5x -8
1) Let's evaluate the domain of x + 5x -8
For the expression x + 5x -8 to be defined, we must have: x -8 ≠ 0
For the expression x + 5 to exist, you must check: x + 5 ≥ 0
2) Let's solve in ℝ: x -8 ≠ 0
ⓘ We add 8 to both sides
Solution obtained: x ≠ 8
3) Let's solve in ℝ: x + 5 ≥ 0
ⓘ We subtract 5 from both sides
Solution found: x ≥ -5
Let's create the table of the different solutions to find the overall solution:
x-∞ -5 8 +∞
x -8 ≠ 0✅✅✅❌✅
x + 5 ≥ 0❌✅✅✅✅
Domain of definition: ❌✅✅❌✅
▶Domain of definition:   x ∈ [-5, 8) ∪ (8, +∞)