1) 3x^2+5x-8=0
2) x^2+5x+10=0
3) 7x^2-14x+7=0
4) -x^2+3x+4=0
5) 4(x-1)^2-16x=0
Ответы на вопрос
Ответил Istercul
0
1.
![3x^2+5x-8=0\
D=25+96=121\
x_1=(-5+11):6=1\
x_2=(-5-11):6=- frac{8}{3}](https://tex.z-dn.net/?f=3x%5E2%2B5x-8%3D0%5C%0AD%3D25%2B96%3D121%5C%0Ax_1%3D%28-5%2B11%29%3A6%3D1%5C%0Ax_2%3D%28-5-11%29%3A6%3D-+frac%7B8%7D%7B3%7D+ "3x^2+5x-8=0\
D=25+96=121\
x_1=(-5+11):6=1\
x_2=(-5-11):6=- frac{8}{3}")
2.
![x^2+5x+10=0\
D=25-40=-15](https://tex.z-dn.net/?f=x%5E2%2B5x%2B10%3D0%5C%0AD%3D25-40%3D-15 "x^2+5x+10=0\
D=25-40=-15")
Т.к. D<0 решения нет
3.
![7x^2-14x+7=0\
D=196-196=0\
x=14:14=1](https://tex.z-dn.net/?f=7x%5E2-14x%2B7%3D0%5C%0AD%3D196-196%3D0%5C%0Ax%3D14%3A14%3D1 "7x^2-14x+7=0\
D=196-196=0\
x=14:14=1")
4.
![-x^2+3x+4=0\
x^2-3x-4=0\
D=9+16=25\
x_1=(3+5):2=4\
x_2=(3-5):2=-1](https://tex.z-dn.net/?f=+-x%5E2%2B3x%2B4%3D0%5C%0A+x%5E2-3x-4%3D0%5C%0AD%3D9%2B16%3D25%5C%0Ax_1%3D%283%2B5%29%3A2%3D4%5C%0Ax_2%3D%283-5%29%3A2%3D-1 "-x^2+3x+4=0\
x^2-3x-4=0\
D=9+16=25\
x_1=(3+5):2=4\
x_2=(3-5):2=-1")
5.
![4(x-1)^2-16x=0 \
x^2-2x+1-4x=0\
x^2-6x+1=0\
D=36-4=32\
x_1=(6+4 sqrt{2} ):2=3+2 sqrt{2} \
x_2=(6-4 sqrt{2} ):2=3-2 sqrt{2}](https://tex.z-dn.net/?f=4%28x-1%29%5E2-16x%3D0+%5C%0Ax%5E2-2x%2B1-4x%3D0%5C%0Ax%5E2-6x%2B1%3D0%5C%0AD%3D36-4%3D32%5C%0Ax_1%3D%286%2B4+sqrt%7B2%7D+%29%3A2%3D3%2B2+sqrt%7B2%7D+%5C%0Ax_2%3D%286-4+sqrt%7B2%7D+%29%3A2%3D3-2+sqrt%7B2%7D+ "4(x-1)^2-16x=0 \
x^2-2x+1-4x=0\
x^2-6x+1=0\
D=36-4=32\
x_1=(6+4 sqrt{2} ):2=3+2 sqrt{2} \
x_2=(6-4 sqrt{2} ):2=3-2 sqrt{2}")
2.
Т.к. D<0 решения нет
3.
4.
5.
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