》a+a+a+a+a= 5a
》m×m×m×m×m= m⁵
》13×23+37×13= 299+481= 780
》(45-12)×3 = 33×3= 99
》34105-2716= 31389
》312+208= 520
》150150-150×[17²-(13²+4³)]=
=150150-150×[17²-(169+64)]=
=150150-150×(289-100)=
=150150-150×189=
=150150-28350=121800
