https://i.imgur.com/7Pm2a4R.jpg
a) \(⇔-4x^2-4x+7x+7=0\)
\(⇔-4x(x+1)+7(x+1)=0\)
\(⇔(x+1)(-4x+7)=0\)
\(⇔\left[\begin{array}{} x+1=0\\ -4x+7=0 \end{array}\right.⇔\left[\begin{array}{} x=-1\\ x=\frac{7}{4} \end{array}\right.\)
b) \(⇔4x^2-8x+3x-6=0\)
\(⇔4x(x-2)+3(x-2)=0\)
\(⇔(x-2)(4x+3)=0\)
\(⇔\left[\begin{array}{} x-2=0\\ 4x+3=0 \end{array}\right.⇔\left[\begin{array}{} x=2\\ x=-\frac{3}{4} \end{array}\right.\)
