Ý bạn có phải là:

Tính nhanh:

\(\frac{26.13+74.14}{\left(315+372\right).3+\left(372+315\right).7}\)

đúng ko?

[ ( 315 + 372 ) x 3 + ( 372 + 315) x 7 ] : ( 26 x 13 + 74 x 14 )

= [(315 +372)(3 + 7)] : (2.13.13 + 74.7.2)

= [687.10] : [2(169 +518)]

= 6870 : [2.687]

= 6870 : 1374 

= 5  

= [ 687 x 3 + 687 x 7 ] : 26 x 13 + 74 x 14 

= [ 687 x ( 3 + 7 ) ] : 26 x 13 + 74 x 14 

= [ 687 x 10 ] : 26 x 13 + 74 x 14 

= 6870 : 26 x 13 + 74 x 14

= 3435 + 1036

= 4471

= [ 687 x 3 + 687 x 7 ] : 26 x 13 + 74 x 14 

= [ 687 x ( 3 + 7 ) ] : 26 x 13 + 74 x 14 

= [ 687 x 10 ] : 26 x 13 + 74 x 14 

= 6870 : 26 x 13 + 74 x 14

= 3435 + 1036

= 4471

= [ 687 x 3 + 687 x 7 ] : 26 x 13 + 74 x 14 

= [ 687 x ( 3 + 7 ) ] : 26 x 13 + 74 x 14 

= [ 687 x 10 ] : 26 x 13 + 74 x 14 

= 6870 : 26 x 13 + 74 x 14

= 3435 + 1036

= 4471

A= 1+5+9+.....+2001

Số số hạng: (2001-1):4+1=501

Tổng là: (2001+1)x501:2=501501

a) B = [ ( 315 + 372 ) . 3 + ( 372 + 315 . 7 ] : ( 26 . 13 + 74 . 14 )

= [687.3+687.7]:1374=6870:1374=5

\(\dfrac{\left(315+372\right).3+\left(372+315\right).7}{26.13+74.14}\)

\(=\dfrac{\left(315+372\right)\left(3+7\right)}{2.13.13+74.2.7}\)

\(=\dfrac{687.10}{2\left(169+518\right)}\)

\(=\dfrac{6870}{2.687}=\dfrac{6870}{1374}=5\)

a, [ (315+372) .3 +(372+315).7] /26.13 +74.14

=[ (315+372) .(3+7) ] /26 .13 + 74 .13 +74

= [(315+372).10 ] / (26+74).13 +74

= 687 .10 / 100.13 +74

= 6870 /1374

den day ban tu rut gon

\(\dfrac{\left(315+372\right).3+\left(372+315\right).7}{26.13+74.14}\)

\(=\dfrac{687.\left(3+7\right)}{26.13+74.13+74}\)

\(=\dfrac{687.10}{13\left(74+26\right)+74}\)

\(=\dfrac{6870}{1374}=5\)