If Ying Zyiyu covers the first 200 miles of a trip going at 50 mph and the last hundred going 40 mph, what was his average speed of the entire trip? Do it fast

Can someone me and plz do the problem

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

(05.03 mc) part a: explain why the x-coordinates of the points where the graphs of the equations y = 4x and y = 2x−2 intersect are the solutions of the equation 4x = 2x−2. (4 points) part b: make tables to find the solution to 4x = 2x−2. take the integer values of x between −3 and 3. (4 points) part c: how can you solve the equation 4x = 2x−2 graphically? (2 points)