HELP I NEED HELP WITH THIS

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

What is the similarity ratio of a cube with volume 729m^3 to a cube with volume 3375 m^3

Given: lines a and b are parallel and line c is a transversal. prove: 2 is supplementary to 8 what is the missing reason in the proof? statement reason 1. a || b, is a transv 1. given 2. ∠6 ≅ ∠2 2. ? 3. m∠6 = m∠2 3. def. of congruent 4. ∠6 is supp. to ∠8 4. def. of linear pair 5. ∠2 is supp. to ∠8 5. congruent supplements theorem corresponding angles theorem alternate interior angles theorem vertical angles theorem alternate exterior angles theorem