Answer
$[10, +\infty)$
Work Step by Step
The radicand (expression inside a radical) of a square root cannot be negative as its root is an imaginary number.
This means that the radicand, which is $7x-70$, must be greater than or equal to 0.
Thus,
$7x-10\ge 0
\\7x \ge 0+70
\\7x \ge 70
\\x \ge \frac{70}{7}
\\x \ge 10$
Therefore, the domain of the given function is $[10, +\infty)$.
