For value of v, determine whether it is a solution to 21=5v+1. is -7 a solution

Quadrilateral abcd in the figure below represents a scaled-down model of a walkway around a historic site. quadrilateral efgh represents the actual walkway. abcd is similar to efgh. what is the total length, in feet of the actual walkway?

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

12 3 4 5 6 7 8 9 10time remaining01: 24: 54which graph represents this system? y=1/2x + 3 y= 3/2x -1