G)5x7x77-7x60+49x25-15x42 
=5x7x77-7x12x5+7x7x5x5-5x3x7x6 
= 5x7(77-12+7x5-3x6) 
=35(77-12+35-18) 
= 35x82 

a)24.53+24.87+24.40

=24.(53+87+40)

=24.180

=4320

b)35.77-7.5.12+7.7.5.5+3.5.7.6

=35.77-35.12+35.35+35.18

=35.(77-12+35+18)

=35.118=4130

^^

Ta có:

5 x 77 x 7 - 7 x 60 + 49 x 25 - 15 x 42

<=> 5 x 77 x 7 - 7 x 5 x 12 - 7 x 7 x 5 x 5 - 3 x 5 x 7 x 6

<=> 5 x 7(77 - 12 - 7 x 5 - 3 x 6)

<=> 35(77 -12 - 35 - 18)

<=> 35 x 15

<=> 525

tính tổng hỏi rứa cũng hỏi

35x15 làm sao tính nhanh đc

=2870

giải ra hộ mk nha tính nhanh đó bạn

\(5.7.27-7.60+49.25-15.42=\left(5.7.27\right)-\left(7.60\right)+\left(49.25\right)-\left(15.42\right)=945-420+1225-630=525+595=1120\)

1, =35 x 77-35 x 12+35x35-35 x 18 suy ra =35 x(77-12+35-18)=35 x 82=2870.

2, =2014 x (100-1)=201400-2014=199386.

3,=35x12+65x12+65=12x(65+35)+65=1200+65=1265.

4.=\(\frac{13\times\left(37-1\right)}{12\times\left(37+2\right)}\)=\(\frac{13\times36}{12\times39}=\frac{13\times3\times12}{12\times3\times13}=1\)

tck nha bạn