Which one is it? ill mark brainliest if correct

Suppose that x and y are both differentiable functions of t and are related by the given equation. use implicit differentiation with respect to t to determine startfraction dy over dt endfraction in terms of x, y, and startfraction dx over dt endfraction .

Need solving this second acceleration problem.

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