What is the negitive square root 64

Me write an equation for the interior angles of this triangle that uses the triangle sum theorem

The tuition costs, c, for a local community college are modeled by c(h) = 250 + 200h, where h represents the number of credit hours taken. the local state university has tuition costs, s, modeled by the function s(h) = 300 + 180h. how many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

Solve the given system of equations. 2y= -x+9 , 3x-6= -15