+9674 Move every term to one side:
\(\begin{array}{rcl} x^2 -13x + 4&=& 5x + 7\\ x^2 - 18x - 3 &=& 0 \end{array}\)
Let a and b be the roots. Then by Vieta's formulae,
\(\begin{cases}a + b =18\\ab=-3\end{cases}\)
Therefore,
\(\begin{array}{cl} &\text{sum of square of roots}\\ =& a^2 + b^2\\ =& (a + b)^2 - 2ab\\ =& 18^2 - 2(-3)\\ =& 330 \end{array}\)
+9674 Move every term to one side:
\(\begin{array}{rcl} x^2 -13x + 4&=& 5x + 7\\ x^2 - 18x - 3 &=& 0 \end{array}\)
Let a and b be the roots. Then by Vieta's formulae,
\(\begin{cases}a + b =18\\ab=-3\end{cases}\)
Therefore,
\(\begin{array}{cl} &\text{sum of square of roots}\\ =& a^2 + b^2\\ =& (a + b)^2 - 2ab\\ =& 18^2 - 2(-3)\\ =& 330 \end{array}\)
