a) 3 - mx = 2 m ( x + 1 ) - 1
3 - mx = 2mx + 2m - 1
3mx = 4 - 2m
x = ( 4 - 2 ) / 3m
b) mx + m + 3 + = x + 4
mx - x = 4 - m - 3
x ( m - 1 ) = 1 - m
x= ( 1 - m ) / ( m - 1 ) = -1
c) 2 ( mx + x )- 3 ( x + 4 ) = 5 - m
2mx + 2x - 3x - 12 = 5 - m
2mx - x - 17 + m = 0
x ( 2 m - 1 ) = 17 - m
x = ( 17 - m ) / ( 2m - 1 )
