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Chelik
4 год назад
Привет помоги даю 55 ь
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ОТВЕТЫ
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Sergej
Dec 1, 2020
Задание 1.
1. x²-8x-9=0
D=(-8)²-4×(-9)=64+36=100
x1=8+10/2=9 x2=8-10/2=-1
: 1.(9,-1)
б) y²+8y+15=0
D=8²-4×15=64-60=4
x1=-8+2/2=-3 x2=-8-2/2=-5
: 4.(-3,-5)
2. x²+17x-38=0 x1=2
D=17²-4×(-38)=289+152=441
x1=-17+21/2=2 x2=-17-21/2=-19
: 3)19
3.x²+bx+18=0 x1=3
x1+x2=-b
x1×x2=c
3+x2=-b
3×x2=18
x2=6
3+6=-b
b=-9
: 2) x2=6, b=-9
4.
x²+5x+c=0 x1=-2
-2+x2=-5
x2=-3
2×(-3)=c
c=-6
: 1) x2=-3, c=-6
380