1) 
0 \\ x_{1,2}= \frac{-b б \sqrt{D} }{2a}= \frac{-5б17}{6} \\ x_{1}=2 \\ x_{2}= -3 \frac{4}{6} " alt="(3x-1)(x+2)=20 \\ 3 x^{2} +6x-x-2=20 \\ 3 x^{2} +5x-2-20=0 \\ 3 x^{2} +5x-22=0 \\ a=3,b=5,c=-22 \\ D= b^{2}-4ac=25+ 264=289>0 \\ x_{1,2}= \frac{-b б \sqrt{D} }{2a}= \frac{-5б17}{6} \\ x_{1}=2 \\ x_{2}= -3 \frac{4}{6} " align="absmiddle" class="latex-formula">
Ответ: 2; 
.
2) 
0 \\ x_{1,2} = \frac{-bб \sqrt{D} }{2a}= \frac{19б11}{8} \\ x_{1}= 3,75 \\ x_{2}=1 " alt="(x-4)(4x-3)+3=0 \\ 4x^{2}-3x-16x+12+3=0 \\ 4x^{2} -19x+15=0 \\ a=4,b=-19,c=15 \\ D= b^{2}-4ac=361-240=121>0 \\ x_{1,2} = \frac{-bб \sqrt{D} }{2a}= \frac{19б11}{8} \\ x_{1}= 3,75 \\ x_{2}=1 " align="absmiddle" class="latex-formula">
Ответ: 3,75; 1.
3) 
0 \\ x_{1,2}= \frac{-bб \sqrt{D} }{2a}= \frac{5б11}{2} \\ x_{1}=8 \\ x_{2}=-3 " alt=" (x-3)^{2}+ (x+4)^{2}- (x-5)^{2}=17x+24 \\ x^{2} -6x+9+ x^{2} +8x+16- ( x^{2} -10x+25)=17x+24 \\ 2 x^{2} +2x+25- x^{2} +10x-25-17x-24=0 \\ x^{2} -5x-24=0\\a=1,b=-5,c=-24 \\ D= b^{2}-4ac=25+96=121>0 \\ x_{1,2}= \frac{-bб \sqrt{D} }{2a}= \frac{5б11}{2} \\ x_{1}=8 \\ x_{2}=-3 " align="absmiddle" class="latex-formula">
Ответ: 8; -3.