phẩy nà ní???

\(a,17,89:25-4,89:25=\left(17,89-4,25\right):25=13:25=0,52\\ b,28+62\times a\times\left(a\times1-a:1\right)+28\times8+28=28+62\times a\times\left(a-a\right)+28\times8+28=28+62\times a\times0+28\times8+28=28+28\times8+28=28\times\left(1+8+1\right)=28\times10=280\)

a) 19,17x25x4=19,17(25x4)=19,17x100=1917

b)1,79x(8x125)=1,79x1000=1790

chúc bạn học tốt

3254 + 146 + 1698

= (3254 + 146) + 1698

= 3400 + 1698

= 5098

--------

142 × 12 + 142 × 18

= 142 × (12 + 18)

= 142 × 30

= 4260

--------

4 × 18 × 25

= (4 × 25) × 18

= 100 × 18

= 1800

--------

302 × 16 + 302 × 4

= 302 × (16 + 4)

= 302 × 20

= 6040

2 × 45 × 5

= (2 × 5) × 45

= 10 × 45

= 450

--------

36 × 2 × 7 × 5

= (36 × 7) × (2 × 5)

= 252 × 10

= 2520

--------

175 × 1250 + 8749 × 175 + 175

= 175 × (1250 + 8749 + 1)

= 175 × 10000

= 1750000

a) \(\dfrac{16}{15}+\dfrac{7}{15}+\dfrac{4}{15}=\left(\dfrac{16}{15}+\dfrac{4}{15}\right)+\dfrac{7}{15}=\dfrac{20}{15}+\dfrac{7}{15}=\dfrac{27}{15}\)

b) \(\dfrac{5}{17}+\dfrac{7}{17}+\dfrac{13}{17}=\dfrac{5}{17}+\left(\dfrac{7}{17}+\dfrac{13}{17}\right)=\dfrac{5}{17}+\dfrac{20}{17}=\dfrac{25}{17}\)

nhanh

=84000:1000=84

=125x8=1000

=125x8=1000

= (125 x 8) x (20 x 50)
= 1000 x 1000
= 1000000

1 000 000

125 x 20 x 8 x 50

= (125 x 8) x (20 x 50)

= 1000 x 1000

= 1.000.000

chúc bạn học giỏi❤