7а +( 2а +3в ) = 7а + 2а +3в= 9а +3в= 3 ( 3а + в )
( 5х +7а ) + 4а = 5х + 7а + 4а =5х + 11а
( 3х - 6у ) - 4х = 3х -6у -4х =- х-6у
5m- ( 5n + 2 m ) = 5m - 5n - 2 m =3m - 5n
9x + ( 2y - 5x ) = 9x +2y - 5x = 4x + 2y
( 5x - 7a ) + 5a =5x - 7a + 5a =5x - 2a
( 2a + 5b ) - 7b = 2a + 5b - 7b = 2a -2b
6p- ( 5p - 3a ) = 6p -5p + 3a =p + 3a