1)×(×-5)=24; 2)×(×+7)=78; 3)×(×+8)=105.

1) Х(Х-5)=24Х^2-5X-24=0X1*X2=-24X1+X2=5X1=-3X2=82) x(x+7)=78x^2+7x-78=0x1*x2=-78x1+x2=-7x1=-13x2=53)x(x+8)=105x^2+8x-105=0x1*x2=-105x1+x2=-8x1=7x2=-15

1. x^2-5x-24=0D=25-4*1*(-24)=25+96=121(корень=11)x1=(5+11)2=8x2=(5-11)2=-32.x^2+7x-78=0D=49-4*1*(-78)=49+312=361 (корень=19)x1=(-7+19)2=6x2=(-7-19)2=-133.x^2+8x-105=0D=64-4*1*(-105)=64+420=484 (корень=22)x1=(-8+22)2=7x2=(-8-22)2=-15