A=4/3+7/6+11/10+16/15+22/21+29/28+37/36+46/45 

A = ( 1 + 1/3 ) + ( 1 + 1/6 ) + ( 1 + 1/10 ) + ( 1 + 1/15 ) + ( 1 + 1/21 ) + ( 1 + 1/28 ) + ( 1 + 1/36 ) + ( 1 + 1/45 )

A = ( 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 ) + - ( 1/3 + 1/6 + 1/10 + 1/15 + 1/21 + 1/28 + 1/36 + 1/45 )

A = 8 + 4/5

A = 44/5

A = 4/3 + 7/6 + 11/10 + 16/15 + 22/21 + 29/28 + 37/36 + 46/45

A = ( 1 + 1/3 ) + ( 1 + 1/6 ) + ( 1 + 1/10 ) + ( 1 + 1/15 ) + ( 1 + 1/21 ) + ( 1 + 1/28 ) + ( 1 + 1/36 ) + ( 1 + 1/45 )

A = ( 1 + 1 + 1 + ... + 1 ) - ( 1/3 + 1/6 + 1/10 + 1/15 + 1/21 + 1/28 + 1/36 + 1/45 )

 25+36+14+83+51+67+29+35

=(25+35)+(36+14)+(83+67)+(51+29)

=60+50+140+80

=(140+60)+(80+50)

=200+130

=330

=(25+35)+(36+14)+(83+67)+(51+29)

=60+50+140+80

=(140+60)+50+80

=200+50+80

=250+80

=330

M = 7 .9 + 14. 27 + 21 . 36 / 21 . 29 + 42 . 81 + 63 . 108 = 7 . 9 (1 + 2.3 + 3.4) / 21( 29 + 2 . 81 + 3 . 108) = 3 . 19 / 29 + 3⁴ . (2 + 2²) = 3 . 19 / 29 + 3⁴ . 6 = 57 / 515

1.a. 86+357+14 = (86+14)+357 = 100+357 = 457

b. 72+69+128 = (72+128) +69 = 200+69 = 269

c. 25.5.4.27.2 = (25.4).(5.2).27=100.10.27=1000.27=27000

d. 28.64+28.36=28.(64+36)=28.100=2800

2. a. 135+360+65+40= (135+65)+(360+40)=200+400=600

b. 463+318+137+22 = (463+137)+(318+22)=600+340=940

c. = (20+30)+(21+29)+...+(24+26)+25

= 50+50+50+50+25

= 225

a,2575-37-2576+29

=2575-37-2575-1+29

=(2575-2575)-37-1+29

=0-37-1+29

=-37-1+29

=-38+29

=-9

b,34+35+36+37-14-15-16

=(34-14)+(35-15)+(36-16)+37

=20+20+20+37

=20x3+37

=60+37

=97

   21/36 x 39/14 x 54/13

= 13/8 x 54/13

= 27/4

\(\frac{21}{36}\)x \(\frac{39}{14}\)x \(\frac{54}{13}\)= \(\frac{189}{82}\).

b) 14/15

c)39/65

b) 14/15 ; 17/51

c) (Mình không thấy có phân số nào rút gọn được nữa)