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Question Number 191254 by anr0h3 last updated on 21/Apr/23

  a=((x−a)/(x−b)) solve for x  did i make anything wrong in the following?    starpoint:  ln∣a∣=ln∣((x−a)/(x−b))∣  ln∣a∣=ln∣x−a∣−ln∣x−b∣  ln∣a∣=ln∣(x/a)∣−ln∣(x/b)∣  ln∣a∣=ln∣x∣−ln∣a∣−(ln∣x∣−ln∣b∣)  ln∣a∣=ln∣x∣−ln∣a∣−ln∣x∣+ln∣b∣  2∙ln∣a∣=ln∣b∣  e^(ln∣a^2 ∣) =e^(ln∣b∣)   a^2 =b  if a^2 =b then  a=((x−a)/(x−b))  a∙(x−b)=(x−a)⇔x−b≠0  a∙x−a∙b=x−a  a∙x−x=a∙b−a  x(a−1)=a∙a^2 −a  x=((a^3 −a)/(a−1))⇔a−1≠0  x=((a(a^2 −1))/(a−1))  x=((a∙(a−1)∙(a+1))/(a−1))  x=a(a+1)  x=b+a    answer:  x=a^2 +a or x=b+a, and x,a,b ∉ C    so now the question is: what if x,a,b ∈ C?

a=xaxbsolveforxdidimakeanythingwronginthefollowing?starpoint:lna∣=lnxaxblna∣=lnxalnxblna∣=lnxalnxblna∣=lnxlna(lnxlnb)lna∣=lnxlnalnx+lnb2lna∣=lnbelna2=elnba2=bifa2=bthena=xaxba(xb)=(xa)xb0axab=xaaxx=abax(a1)=aa2ax=a3aa1a10x=a(a21)a1x=a(a1)(a+1)a1x=a(a+1)x=b+aanswer:x=a2+aorx=b+a,andx,a,bCsonowthequestionis:whatifx,a,bC?

Commented by mr W last updated on 23/Apr/23

first:  ln (a−b)≠ln (a/b), therefore  ln (a−b)≠ln a−ln b    second:  if a=(b/c), then ac=b    third:  when x=a^2 +a or x=b+a, why  should x,a,b ∉C?    fourth:  when somebody even doesn′t know   a=(b/c) ⇒ ac=b, how can he understand  complex numbers?    etc.

first:ln(ab)lnab,thereforeln(ab)lnalnbsecond:ifa=bc,thenac=bthird:whenx=a2+aorx=b+a,whyshouldx,a,bC?fourth:whensomebodyevendoesntknowa=bcac=b,howcanheunderstandcomplexnumbers?etc.

Commented by mr W last updated on 21/Apr/23

therefore  a=((x−a)/(x−b))  a(x−b)=x−a  ax−ab=x−a  (a−1)x=a(b−1)  x=((a(b−1))/(a−1))   (a≠1)

thereforea=xaxba(xb)=xaaxab=xa(a1)x=a(b1)x=a(b1)a1(a1)

Commented by JDamian last updated on 21/Apr/23

you seem to misunderstand the exponential function properties

Commented by mehdee42 last updated on 21/Apr/23

ln∣((x−a)/a)∣−ln∣x−b∣=0⇏e^(ln∣((x−a)/a)∣) −e^(ln∣x−b∣) =1

lnxaalnxb∣=0elnxaaelnxb=1

Commented by JDamian last updated on 21/Apr/23

e^(x−y)  ≠ e^x −e^y

exyexey

Commented by anr0h3 last updated on 21/Apr/23

ok thanks

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