65x28+33x28-144
=(65+33)x28-144
=98x28-144
=(100-2)x28-144
=2800-56-144
=2800-(56+144)
=2800-200
=2600
=28*（65+33）-144=28*（100-2）-144=2800-56-144=2800-（144+56）=2800-200=2600
