Х^2-9х+14=0 x^2-11х+30=0 4x^2-20х+21=0 9x^2-12х-5=0 - вопрос №2005415291402113004220210921250 от MRSAVVA 23.07.2021 23:23

Question

Алгебра: Х^2-9х+14=0 x^2-11х+30=0 4x^2-20х+21=0 9x^2-12х-5=0

MRSAVVA · Answer

х^2-9х+14=0D=b^2-4ac=(-9)^2-4*1*14=81-56=25VD=V25=5x1 = 9+5/2*1=14/2=7x2 = 9-5/2=4/2=2x^2-11х+30=0D=(-11)^2-4*1*30=121-120=1VD=V1=1x1=11+1/2=12/2=6x2 = 11-1/2=10/2=54x^2-20х+21=0D=(-20)^2-4*4*21=400-336=64VD=V64=8x1=20+8/2*4 = 28/8= 3,5x2 = 20-8/2*4=12/8 = 1,59x^2-12х-5=0d=(-12)^2-4*9*(-5)=144+180=324VD=V324=18x1=12+18/2*9=30/18 = 1 12/18x2=12-18/2*9=-6/9 = - 2/3...