Ta có : 28,3 - 13,6 - 4,4 

           = 28,3 - ( 13,6 + 4,4 )

          = 28,3 - 18

           = 10,3

# chúc bạn học tốt #

\(a,=28,3-\left(13,6+4,4\right)\\ =28,3+18=46,3\\ b,=\left(218,76-18,26\right)-30,5\\ =100,5-30,5=70\)

a) 28,3-13,6-4,4 = 28,3-(13,6+4,4) = 28,3-18 = 10,3

b) = 218,76-18,26-30,5 = 200,5-30,5 = 170

c) = 94,57-(38,75-18,75)-(43,35+21,22) = 94,57-20-54,57 = 40-20 = 20 

a: =28,3-18=10,3

b: =218,76-18,26-30,5=200,5-30,5=170

4,4 \(\times\) 76 + 2,2:0,5 \(\times\) 10 + 4,4: 0,25 + 4,4:0,1

= 4,4 \(\times\) 76 + 2,2 \(\times\) 2 \(\times\) 10 + 4,4 \(\times\) 4 + 4,4 \(\times\) 10

= 4,4 \(\times\) 76 + 4,4 \(\times\) 10 + 4,4 \(\times\) 4 + 4,4 \(\times\) 10

= 4,4 \(\times\) ( 76 + 10 + 4 + 10)

= 4,4 \(\times\) { (76+4) + (10+10)}

= 4,4 \(\times\) ( 80 + 20)

= 4,4 \(\times\) 100

= 440

4,58* 6,7+ 4,58* 28,3+ 4,58* 65

= 4,58 x ( 6,7 + 28,3 + 65 ) 

= 4,58 x 100

= 458 

4,58 * 6,7 + 4,58 * 28,3 + 4,58 * 65

= 4,58 * (6,7+28,3+65)

=4,58 * 100

= 458

=4.58x(6.7+28.3+65)=4.58x100=458

a: =72,5*13,5-61,5-13,6-13,6

=978,75-61,5-27,2

=890,05

b: =132,5(2+4+8+6)

=132,5*20=2650

`132,5xx2+132,5xx4+132,5:0,125+132,5xx6`

`=132,5xx2+132,5xx4+132,5:1/8+132,5xx6`

`=132,5xx2+132,5xx4+132,5xx8+132,5xx6`

`=132,5xx(2+4+8+6)`

`=132,5xx20`

`=2650`

`72,25xx13,5-13,6-61,5-9,3-4,3`

`=145xx0,5xx0,5xx27-(13,6+61,5+9,3+4,3)`

`=0,25xx145xx27-88,7`

`=36,25xx27-88,7`

`=978,75-88,7`

`=890,05`

a)168,7 x 5,6 + 4,4 x 168,7

= 168,7 x (5,6 + 4,4)

= 168.7 x 10

= 1687

b) 24,58 x 99 + 24,58

= 24,58 x (99 + 1)

= 24,58 x 100

= 2458

Đúng 100% nên yên tâm nhé :))