137 + 5(45-3x)=237
5(45-3x)=100
45-3x=20
3x=25
x=25/3
137 + 5 . ( 45 - 3 . x ) = 237
5 . ( 45 - 3 . x ) = 237 - 137
5 . ( 45 - 3 . x ) = 100
( 45 - 3 . x ) = 100 : 5
( 45 - 3 . x ) = 20
3 . x = 45 - 20
3 . x = 25
x = 25 : 3
x = $\dfrac{25}{3}$.
`137 + 5 . ( 45 - 3.x) = 237`
`5 . ( 45 - 3.x) = 237 - 137`
`5 . ( 45 - 3.x) = 100`
`45 - 3.x = 100 : 5`
`45-3.x = 20`
`3.x =45 - 20`
`3.x = 25`
`x= 25:3`
`x=25/3`