[tex]b)\\\\(4-5x)(2+x)=-(4+5x^2)\\\\8+4x-10x-5x^2=-4-5x^2\\\\-6x-5x^2+5x^2=-4-8\\\\-6x=-12\ \ |:(-6)\\\\x=2[/tex]
[tex]c)\\\\ 4x^2-2x=(2x+1)(2x-3)\\\\4x^2-2x= 4x^2-6x+2x-3\\\\4x^2-2x= 4x^2-4x -3\\\\4x^2-2x-4x^2+4x= -3\\\\2x= -3\ \ |:2\\\\x=-\frac{3}{2}=-1\frac{1}{2}[/tex]
[tex]d)\\\\ 3x(2x+5)=(x+3)(6x+1)\\\\ 6x^2+15x=6x^2+x+18x+3\\\\6x^2+15x=6x^2 +19x+3\\\\6x^2+15x-6x^2-19x=3\\\\-4x=3\ \ |:(-3)\\\\x=-\frac{3}{4}[/tex]
