60+65+70+75+80+85+90+95=(60+95)+(65+90)+(70+85)+(75+80)
=155+155+155+155
=155x4
=620
(60 + 95) + (65 + 90) + (70 + 85) + (75 + 80) = 155 + 155 + 155 + 155 = 155 nhân 4= 620
60 + 65 + 70 + 75 + 80 + 85 + 90 + 95
= ( 60 + 95 ) + ( 65 + 90 ) + ( 70 + 85 ) + ( 75 + 80 )
= 155 + 155 + 155 + 155
= 155 x 4
= 620.
Tính nhanh:
60 + 65 + 70 + 75 + 80 + 85 + 90 + 95
= (60 + 95) + ( 65 + 90) + ( 70 + 85 ) + ( 75 + 80)
= 155+ 155 + 155 + 155
= 155 x 4
= 620
( Ủng hộ tui nha! thanks)
60+65+70+75+80+85+90+95
=(60+70+80+90)+(65+75+85+95)
=300+320
=620