1)145     2)255        3)3110      4)23        5)187

6)216     7)1216,9      8)366      9)620     10)1485

11)11     12)1598

nhé chị

^.^

1)  98 + 47 = 145

2) 199 + 56 = 255

3) 2997 + 113 = 3110

4) 121 - 98 = 23

5) 286 - 99 = 187

6) 1213 - 997 = 216

7) 44801 : ( 448 : 14 ) = 44801 : 32 =44801/32

8) ( 317 + 49 ) - 117 = 366 - 117 = 249

9) 867 - ( 167 + 80 ) = 867 - 247 = 620

10) ( 1578 + 285 ) - 378 = 1863 - 376 = 1485

11) 853 - ( 89 + 753 ) = 853 - 89 - 753 = ( 853 - 753 ) - 89 = 100 - 89 = 11

12) 1637 - ( 137 - 89 ) = 1637 - 137 + 89 = 1500 + 89 = 1589

a)24579 + 43867 = 68446

82604 - 35246 = 47358

b)235 x 325 = 76 375

bang 2500 va 1672 nhe

a.263

b.-234

c.-167

a, 1000 - ( 137 + 572 ) + ( 263 - 291 )=263

b, ( -1999 ) - ( 234 - 1999 )=-234

c, ( 435 - 167 - 89 ) - ( 435 - 89 )=-167

a) |-137| + |-363|=137 + 363 = 500;   

b) |-28| - |98| = 28 – 98 = -(98 – 28) = - 70;

c) (-200) - |-25|.|3| = (-200) – 25 . 3 = (-200) – 75 = -(200 + 75) = -275

a: =137+363=500

b: =28-98=-70

c: =-200-75=-275

a=154-137=17

b=187-154=33

c=167-157=13

d=187-154=33

a+b+c+b+c+d+c+d+a+d+a+b

=> 3a+3b+3c+3d=154+137+187+167=645

=> 3(a+b+c+d)=645

=> a+b+c+d=215

=> d=215-(a+b+c)=215-154=61

=> a=215-(a+c+d)= 215-137=78

=> b=215-(c+d+a)=215-187=28

=> c=215-(d+a+b)=215-167=48

Vậy a=78;b=28;c=48;d=61

a+b+c+d=(154+137+187+167):3

a+b+c+d=215

a=215-137=78

b=215-187=28

c=215-167=48

d=215-154=61

[ 167 x 235 ] + [ 145 x 598 ]

= 39245 + 86710

= 125955

[167*235]+[145*598]

=39245   +  86710

=      125955

hoshimiya ichigo à,k mk nha,mk nhanh nhất đó!!!