Question

39*43-13*29怎么简便计算

明天交作业，求各位大神帮助

Answer 1

40×43-43-13×30-13 =10×43+10×43+10×43+10×43-43-＜13×10+13×10+13×10-13＞=430+430+430+430-43-＜130+130+130-13＞=860+860-43-390+13=1720-43-390+13=1720-390-30=1720-420=1300

Answer 2

39*43-13*29
=13*3*43-13*29
=13*129-13*29
=13*(129-29)
=13*100
=1300