tính A= 1+5+9+......2001
tính B= (315+372). 3+(372+315). 7 : 26. 13+74. 14
Bài 9: Tính
a) 1 + 7 + 8 + 15 + 23 + …. + 160;
b) 1 + 4 + 5 + 9 + 14 + …. + 60 + 97;
c) 78. 31 + 78. 24 + 78. 17 + 22. 72.
d) (456. 11 + 912). 37 : 13 : 74
e) [(315 + 372). 3 + (372 + 315). 7] : (26. 13 + 74. 14)
bai 1: Thuc hien phep tinh
a) B = [ ( 315 + 372 ) . 3 + ( 372 + 315 . 7 ] : ( 26 . 13 + 74 . 14 )
a) B = [ ( 315 + 372 ) . 3 + ( 372 + 315 . 7 ] : ( 26 . 13 + 74 . 14 )
= [687.3+687.7]:1374=6870:1374=5
[ ( 315 + 372 ) x 3 + ( 372 + 315 x 7 ] : ( 26 x 13 + 74 x 14 )
[ ( 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
1. Tính nhanh
a, (315+372)×3+(372+315)×7/26×13+74×14
\(\dfrac{\left(315+372\right).3+\left(372+315\right).7}{26.13+74.14}\)
\(=\dfrac{\left(315+372\right)\left(3+7\right)}{2.13.13+74.2.7}\)
\(=\dfrac{687.10}{2\left(169+518\right)}\)
\(=\dfrac{6870}{2.687}=\dfrac{6870}{1374}=5\)
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
\(\dfrac{\left(315+372\right).3+\left(372+315\right).7}{26.13+74.14}\)
\(=\dfrac{687.\left(3+7\right)}{26.13+74.13+74}\)
\(=\dfrac{687.10}{13\left(74+26\right)+74}\)
\(=\dfrac{6870}{1374}=5\)
[ (315 +372 ) . 3 + ( 372 +315 ) . 7 ] : ( 26 .13 + 74 . 14 )
Thực hiện phép tính
tính :
(315 + 372) .3 + (372 + 315) . 7
26 . 13 + 74 . 14
thực hiện phép tính hợp lí.
a) A= ( 456 x11 + 912) x 37 : 13 :74
b) B= [ ( 315 + 372 ) x 3 + ( 372 + 315) x 7]: ( 26 x 13 + 74 x 14 )
a) A= ( 5016+912).37:13:74
A= 5928.37:13:74
A=219336:13:74
A=16872:7
A=228
b) B=[687.3+687.7]:(338+1036)
B=687.(3+7):1374
B=687.10:1374
B=6870:1374
B=5
Tính: [(315+372) x3 + (372 + 315) x 7] : 26 x 13 + 74 x 14=
= [ 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
Thực hiện phép tính
A) ( 315 + 372 ) x 3 + ( 372 + 315 ) x 7 / 26 x 13 + 74 x 14