Answer:
[tex]x_1=-\frac{b}a,x_2=-\frac{d}c[/tex]
Step-by-step explanation:
Solving for x:
[tex]ax(cx + d) =-b(cx +d)\\ax(cx + d)+b(cx+d)=0\\(ax+b)(cx+d)=0[/tex]
In this form is easy to identify the factors of the quadratic function: [tex](ax+b)(cx+d)[/tex]. The two solutions are the values that make each of the factors equals to zero.
[tex]ax_1+b=0\\ax_1=-b\\x_1=-\frac{b}a\\cx_2+d=0\\cx_2=-d\\x_2=-\frac{d}c[/tex]