In my math class one of the questions on an assignment says to "Solve using the quadratic equation and round answer to the hundredths. when I put the equation into desmos plugging in the correct numbers into the respective slots I get undefined instead of an answer. The top line is the equation with the numbers plugged in the middle is the problem and the bottom is the equation we are supposed to be using to find x.

b² is (-12)² which is 144, not -144.

Your entire square root is negative, which is undefined as far as this is concerned. Get rid of that negative and you’ll be correct.