[tex]1a)\\\\(2x-1)^2+3(3x-5)(3x+5)=4x^2-4x+1+3(9x^2-25)=\\\\=4x^2-4x+1+27x^2-75=31x^2-4x-74\\\\b)\\\\(3x+5)^2-(x-6)^2+2(4x-1)(4x+1)=\\\\=9x^2+30x+25-(x^2-12x+36)+2(16x^2-1)=\\\\=9x^2+30x+25- x^2+12x-36 +32x^2-2=\\\\=40x^2+42x-13[/tex]
[tex]2)\\\\ (2x+4)^2-3(x-1)^2-2(y+x)(y-x)+4xy=\\\\=4x^2+16x+16-3(x^2-2x+1)-2(y^2-x^2)+4xy=\\\\=4x^2+16x+16-3 x^2+6x-3-2 y^2+2x^2 +4xy=\\\\=3x^2+4xy+22x-2y+13\\\\x=0,5=\frac{5}{10}=\frac{1}{2},\ \ \ \ y=-1,2=-\frac{12}{10}=-\frac{6}{5}\\\\3x^2+4xy+22x-2y+13=3 *(\frac{1}{2})^2+4*\frac{1}{2} *(-\frac{6}{5}) +22 *\frac{1}{2}-2 *(-\frac{6}{5})+13=\\\\=3 * \frac{1}{4 } +2 *(-\frac{6}{5}) +\frac{12}{5} +13= \frac{3}{4} -\frac{12}{5} +2\frac{ 2}{5} +24= \frac{3}{4} -2\frac{12}{5} +2\frac{ 2}{5} +24=24\frac{3}{4}[/tex]
