(3x)to the power of lg3 is equal to (4x)to the power of lg4

• gobez14

  28 Jan 08, 19:40

  Solve fer x ..

  i noe the answer it is 1/12 but how to get!?

   

  pls help

• ^tamago^

  28 Jan 08, 19:44

  (3x)^{lg 3} = (4x)^{lg 4}

• gobez14

  28 Jan 08, 19:46

  how to get!!!????

• ^tamago^

  28 Jan 08, 19:53

  (3x)^{lg 3} = (4x)^{lg 4}

  Taking lg,
  lg 3 lg 3x = lg 4 lg 4x
  lg 3(lg 3 + lg x) = lg 4(lg 4+lg x)
  (lg 3)² - (lg 4)² = -lg x(lg 3 - lg 4)
  -lg x = lg 3 + lg 4 = lg 12
  lg x = lg 12^-1 = lg (1/12)
  x = 1/12

• gobez14

  28 Jan 08, 21:00

  tahnkew so much tammy

• ^tamago^

  28 Jan 08, 21:21

  it's okie