\begin{tabular}{l|l|}\hline 2. Explain to someone who missed class how you would write \( (3-5 i)(-2+4 i) \) in the form \( a+b i \), \\ where a and b are real numbers. \end{tabular}

17. \( 5 x^{2}+12 x-2=0 \)

Find the indicated value of the function \( f(x, y, z)=6 x-5 y^{2}+5 z^{3}-7 \). \( f(6,-6,3) \) \( f(6,-6,3)=\square \)

12.3 The equations \( x^{2}+a x+b=0 \) and \( x^{2}+b x+a=0 \) both have real and equal roots. Solve for \( a \) and \( b \), where \( a>0 \) and \( b>0 \).

24 Expresa com a identitats notables. \( \begin{array}{ll}\text { a) } 49 x^{2}-16 & \text { b) } 36 x^{2}-1 \\ \text { c) } x^{2}-18 x+81 & \text { d) } 121-100 x^{2} \\ \text { e) } 9 x^{2}+12 x+4 & \text { f) } 9 x^{2}-24 x+16 \\ \text { g) } 25-100 y^{2} & \text { h) } 4 x^{2}+16 x+16\end{array} \)

15. \( 5 x^{2}-47 x=156 \)