Matemáticas, pregunta formulada por thalia48, hace 1 año

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Contestado por MATHCAOF2017
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Resolver:

1) 20 x^{2} +3x-2=0

Aplicando la formula general: 

x1 =  \frac{-b+ \sqrt{b^2-4ac} }{2a} =  \frac{-3+ \sqrt{3^2-4.20.(-2)} }{2.20} =  \frac{-3+ \sqrt{9+160} }{40} =  \frac{-3+ \sqrt{169} }{40} =  \frac{-3+13}{40}
= \frac{x}{y}  \frac{10}{40}=  \frac{1}{4} = 0,25

x2=\frac{-b- \sqrt{b^2-4ac} }{2a}= \frac{-3- \sqrt{3^2-4.20.(-2)} }{2.20} = [tex]\frac{-3- \sqrt{9+160} }{40} = \frac{-3- \sqrt{169} }{40} = \frac{-3-13}{40} = \frac{x}{y} \frac{-16}{40}= \frac{-4}{10} =  \frac{-2}{5}[/tex] =-0,40

2)
5z^2=17z+14 =0

x1= \frac{-(-17)+ \sqrt{(-17)^2-4.5.14} }{2.5} = \frac{17+ \sqrt{289-280} }{2.5} =  \frac{26}{10} =  \frac{13}{5} = 2,6

x2= \frac{-(-17)- \sqrt{(-17)^2-4.5.14} }{2.5} = \frac{17- \sqrt{289-280} }{2.5} = \frac{14}{10} = \frac{7}{5} = 1,4

3) 
10w^2-7w-6 = 0 

x1= \frac{-(-7)+ \sqrt{(-7)^2-4.10.(-6)} }{2.10} = \frac{7+ \sqrt{49+240} }{20} = \frac{24}{20} = \frac{6}{5} = 1,20

x2= \frac{-(-7)- \sqrt{(-7)^2-4.10.(-6)} }{2.10} = \frac{7- \sqrt{49+240} }{20} = \frac{-10}{20} =- \frac{1}{2} = -0,50

4)
14 x^{2} +17x-6=0

x1= \frac{-17+ \sqrt{(-17)^2-4.14.(-6)} }{2.14} = \frac{-17+ \sqrt{289+336} }{28} = \frac{8}{28} = 0,29

x2= \frac{-17- \sqrt{(-17)^2-4.14.(-6)} }{2.14} = \frac{-17- \sqrt{289+336} }{28} = -\frac{42}{28} = -1,50
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