решите уравнения x^2+x-12=0    x^2=12x+33=0      7x^-43x-42=0

1: Д=1+48=49=7^2Х1=-1-7/2=-4Х2=-1+7/2=32:Д=144-132=12=2√ 3Х1=-12+2√ 3)/2Х2=-12-2√ 3)/23:Д=1849+1176=55^2Х1=(43+55)/14=7Х2=(43-55)/14=-6/7