Question

calculati : ( x + 1 ): 10 +1 = 9 : ( x + 2 )

Answer 1

( x + 1 ): 10 +1 = 9 : ( x + 2 )


e mai complicat

deci x+1/10+1=9/x+2
x+1/10+1-9/x+2=0
(x+2)(x+1)+10(x+2)-90/10(x+2)=0
x²+x+2x+2+10x+20-90/10(x+2)=0
x²+13x-68=0

x=-13±√13²-4•1•(-68)/2•1
x=-13±√169+272/2
x=-13±√441/2
x=-13±21/2

unde x=-13+21/2
iar x=-13-21/2

deci x=4
x=-17