9less than a number is at most the same number divided by 2

An energy plant is looking into putting in a system to remove harmful pollutants from its emissions going into earth's atmosphere. the cost of removing the pollutants can be modeled using the function c = 25000p/100 -p what is the vertical asymptote?

Solve x+3y=6 and 4x-6y=6 by elimination . show work !

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