Solve the equation by using the quadratic formula -5n^2-12n-1=0

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

Louis wants to carpet the rectangular floor of his basement the basement has an area of 864 square feet the width of the basement is 2/3 its length what is the length of lewis's basement

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.