a)
[tex](x+3)(1-2x)+2x^2=0\\\\x-2x^2+3-6x+2x^2=0\\\\-5x+3=0 \ \ /-3\\\\-5x=-3 \ \ /:(-5)\\\\\huge\boxed{x=\frac{3}{5}}[/tex]
b)
[tex](x+4)(x-1)=x(x+2)+9x-1\\\\x^2-x+4x-4=x^2+2x+9x-1\\\\x^2+3x-4=x^2+11x-1\\\\x^2+3x-x^2-11x=-1+4\\\\-8x=3 \ \ /:(-8)\\\\\huge\boxed{x=-\frac{3}{8}}[/tex]
c)
[tex]x^2-(x+3)(x-3)=9\\\\x^2-(x^2-3x+3x-9)=9\\\\x^2-(x^2-9)=9\\\\x^2-x^2+9=9 \ \ /-9\\\\0=0[/tex]
Równanie tożsamościowe, ma nieskończenie wiele rozwiązań.
d)
[tex](x+2)(x-3)=x^2+4\\\\x^2-3x+2x-6=x^2+4\\\\x^2-3x+2x-x^2=4+6\\\\-x=10 \ \ /:(-1)\\\\\huge\boxed{x=-10}[/tex]
