Fill in the blank with a constant, so that the resulting quadratic is the square of a binomial. x^2 + 4x + 5x + ___
+1223 We can complete the square. After simplifying, we get x^2 + 9x.
This simplifes to \(x^2 + 9x = (x + \frac{9}{2})^2 - \frac{81}{4}\). So, the constant is 81/4.
