Question

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

Answer 1

Answer:

√(7·x + 14) + √(7 - x)

7·x + 14 ≥ 0 --> x ≥ -2

7 - x ≥ 0 --> x ≤ 7

x ∈ [-2 ; 7]