I'm thinking of a number. My number has the property that its square is equal to $270$ more than five times the number. Enter all numbers that have this property.
Let your number be x, a variable. x has the property that x^2 = 5x + 270; x^2 - 5x - 270 = 0
By quadratic formula, x=5±5√552, which are your two numbers that you may be thinking of.
+965 
