b1:4^10.8^15 = (2^2)^10.(2^3)^15 = 2^20.2^45 = 2^65

\(\frac{18.987+9.354.2-3.621.6}{72}\)

\(=\frac{72.\frac{987}{4}+72.\frac{354}{4}-72.\frac{621}{4}}{72}\)

\(=\frac{72.\frac{987+354+621}{4}}{72}\)

\(=\frac{1962}{4}=490,5\)

=180+144-216+144

=144+(216-180)

=144+36

=180

Đ/S : 180

=180 nha ban 

   36 x 5 + 72 x 2 - 216 + 144

= 36 x 5 + 36 x 2 x 2 - 36 x 6 + 36 x 4

= 36 x ( 5 + 2 + 2 - 6 + 4 )

= 36 x       5

=    180

 72:54-72:45

=72:(54-45)

=72:9

=8

72 : 54 - 72 : 45

= 72 : ( 54 - 45 )

= 72 : 9

= 8

72 : 54 - 72 : 45 = 72 : (54 - 45) = 72 : 9 = 8

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

Bằng 96 nha

a) `1/2 xx 5/4 + 1/2 xx 3/4 + 1/2`

`=1/2 xx (5/4 + 3/4 + 1)`

`=1/2 xx 3`

`=3/2`

b) `72/95 xx 64/72 xx 95/72 xx 14/86 xx 72/64 xx 86/14`

`=(72xx64xx95xx14xx72xx86)/(95xx72xx72xx86xx64xx14)`

`= 1`.

a)1/2.(5/4+3/4+1)

=1/2.3

=3/2

b)=(72/95.95/72).(64/72.72/64).(14/86.86/14)

=1.1.1=1

18 x (37/42+37/56+37/72)

=18 x 37/18

=37