26.5-26.8 (б, г) решите плиз

26.5(б,г)
б) $x^{2} -15x+14=0 \\ D= b^{2} -4ac= (-15)^{2} -4*1*14=225-56=169 \\ \sqrt{D} = \sqrt{169} =13 \\ x_{1} = \frac{15+13}{2} =14 \\ x_{2} = \frac{15-13}{2} =1 \\$ $\\$
г) $D= (-19)^{2} -4*1*18=289 \\ \sqrt{D} = \sqrt{289} =17 \\ x_{1} = \frac{19+17}{2}=18 \\ x_{2} = \frac{19-17}{2} =1$

26.8
б) $D= (-26)^{2} -4*1*(-120)=1156 \\ \sqrt{D} =34 \\ x_{1} = \frac{26+36}{2} =30 \\ x_{2} = \frac{26-36}{2} =-5$ $\\$
г) $D= 35^{2} -4*1*(-114)=1681 \\ \sqrt{D} =41 \\ x_{1} = \frac{-35+41}{2} =3 \\ x_{2} = \frac{-35-41}{2} =-38$