Question

como resolver essa equação do segundo grau?
$(15 + x)( \frac{3000 }{x} - 10) = 3000$
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Answer 1

Resposta:

(15+x) *(300/x -10)=3000

multiplique tudo por x

x * (15+x) *(300/x -10)=3000 * x

(15+x) *x *(300/x -10)=3000 * x

(15+x) *(300 -10x)=3000 * x

15 * (300 -10x) + x* (300 -10x) = 3000x

4500 -150x +300x -10x² =3000x

divida tudo por 10

450 -15x +30x -x² =300x

450 +15x-x²=300x

x²-15x-450+300x = 0

x²+285x -450=0

x'=[-285 + √(285²+4*450)]/2 = [-285 + √83025]/2

x'=[-285+45√41]/2

x''=[-285 - √(285²+4*450)]/2 = [-285 - √83025]/2

x''=[-285-45√41]/2