sqrt(x-1)>2
Let's solve in ℝ: x -1 > 2
Isolate the square root: x -1 > 2. Since both sides are nonnegative, square both sides, which keeps the direction of the inequality:
x -1 > 22
ⓘ An integer power is a repeated product: 22 = 2·2 = 4
x -1 > 4
ⓘ We add 1 to both sides
x > 4 + 1
ⓘ Start from 4 and move forward 1 on the number line: 4 + 1 = 5
Candidates, pending the domain check: x > 5
Let's find the domain of x -1 > 2
For the expression x -1 to exist, you must check: x -1 ≥ 0
ⓘ We add 1 to both sides
Domain constraints: x ≥ 1
▶Solution:   x > 5