solve sqrt(x+5)=4
Let's solve in ℝ: x + 5 = 4
We isolate the square root: x + 5 = 4. Since the right side is nonnegative, square both sides:
x + 5 = 42
ⓘ A power with a positive integer exponent is a repeated product: 42 = 4·4 = 16
x + 5 = 16
ⓘ Subtract 5 from both sides
x = 16 -5
ⓘ Start from 16 and move back 5 on the number line: 16 -5 = 11
Candidates, pending the domain check: x = 11
Let's evaluate the domain of x + 5 = 4
For the expression x + 5 to be defined, we must have: x + 5 ≥ 0
ⓘ Subtract 5 from both sides
Domain constraints: x ≥ -5
▶Solution:   x = 11