Sneak Preview Problem: Report Error Fill in the blank with a constant, so that the resulting quadratic is the square of a binomial.\\( \[x^2 + \dfrac{4}{5}x + \underline{~~~~}\]\)
Completing the square: \(\displaystyle \left( x + \frac{4}{5} \right)^2 = x^2 + \frac{4}{5} x + \frac{16}{25}\)
Constant = 16/25
take 1/2 of the 'x' coefficient and add it to the equation
1/2 * 4/5 = 4/10 squared = 16/100 or 8/50 or 4/25