Question 747148
the setup is direct:

{{{
(151-x  )/( 181-x )=3/4
}}}

Now we'll solve as a proportion:


{{{
4(151-x  )=3( 181-x )
}}}


{{{
4(151)-4x  =3( 181)-3x
}}}


{{{
4(151)-3( 181) =4x -3x
}}}


which simplifies to x=61


:)