tính nhanh
a, 53.39+47.39-53.21-47.21
b,2.53.12+4.6.87-3.8.40
c, 5.7.77-7.60+49.25-15.42
Tính nhanh:
a)53.39+47.39-53.21-47.21
b)2.53.12+4.6.87-3.8.40
c)3.7.77-7.60+49.25-15.42
a, 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21
= 53 x (39-21) + 47 x (93-21)
=53 x 18 + 47 x 18
= (53 +47) x 18
= 100 x18
=1800
b,2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
=24 x 53 + 24 x 87 - 24 x 40
=24 x (53+87-40)
=24 x 100 =2400
c,5 x 7 x 77 - 7 x 60 +49 x 25 -15 x 42.
=5 x 7 x 77 - 7 x 5 x 12 +49 x 5 x 5 - 5 x 3 x 42.
=5 x 539 - 84 x 5 +245 x 5 -5 x 126
=5 x (539 - 84 +245 -126)
=5 x 574
=2870
\(a,53\cdot39+47\cdot39-53\cdot21-47\cdot21\)
\(=39\cdot\left(53+47\right)-21\cdot\left(53+47\right)\)
\(=39\cdot100-21\cdot100\)
\(=100\cdot\left(39-21\right)=100\cdot18\)
\(=1800\)
\(b,2\cdot53\cdot12+4\cdot6\cdot87-3\cdot8\cdot40\)
\(=24\cdot53+24\cdot87-24\cdot40\)
\(=24\cdot\left(53+87-40\right)\)
\(=24\cdot100=2400\)
a/39.(53+47)-21.(53-47)
=39.100-21.6
=3900-126
=3774
b);c) tự làm
tính nhanh
53.39+47.39+53.21+47.21
2.53.12+4.6.87 -3.8.40
5.7.77-7.60+49.25-12.42
Tính nhanh
a,53.39 + 47.39 - 53.21 - 47.21
b, 2.53.12 + 4.6.87 - 3.8.40
c, 5.7.77 - 7.60 + 49.25 - 15.42
a, = ( 53 + 47 ) . 39 - ( 53 + 47 ) . 21
= 100 . 39 - 100 . 21
= 100 . ( 39 - 21 )
= 100 .18
= 1800
b, = 24 . 53 + 24 . 87 - 24 . 40
= 24 . ( 53 + 87 - 40 )
= 24 . 100
= 2400
c, = 5.7.77 - 7.60 + 7.7.25 - 15 . 7 .6
= 7 . ( 5 .77 - 60 + 7 . 25 - 15 . 6 )
= 7 . ( 385 - 60 + 175 - 90 )
= 7. 410
= 2870
dấu chấm trong bài là dấu phẩy hay dấu nhân
bạn lê phan joly
....
tính nhanh
a , 53.39+47.39-53:21+47.21
b , 2.53.12+4.6.87-3.8.40
c , 5.7.77-7.60+49.25-15.42
d , 100+98+96+ ...+2-97-95- ... -1
a/ 53.39+47.39-53:21+47.21=488447619
b/2.53.12+4.6.87-3.8.40=6860208
c/5.7.77-7.60+49.25-15.42=2870
1.tính nhanh
53.39+47.39+53.21+47.39
2.53.13+4.6.87+3.8.40
5.7.77+7.60+49.25+15.42
53 . 39 + 47 . 39 - 53 . 21 - 47 . 21
= 53 . (39-21) + 47 . (93-21)
=53 . 18 + 47 . 18
= (53 +47) . 18
= 100 .18
=1800
2 . 53 . 12 + 4 . 6 . 87 - 3 . 8 . 40
=24 . 53 + 24 . 87 - 24 . 40
=24 . (53+87-40)
= 24 . 100
= 2400
5 . 7 . 77 - 7 . 60 +49 . 25 -15 . 42.
= 5 . 7 . 77 - 7 . 5 . 12 + 49 . 5 . 5 - 5 . 3 . 42.
= 5 . 539 - 84 . 5 +245 . 5 -5 . 126
= 5 . (539 - 84 + 245 -126)
= 5 . 574
= 2870
Tính nhanh
17.93+116.83+17.23
19.27+47.81+19.20
87.23+13.93+70.87
78+31+78.24+78.17+22.72
136.23+136.17-40.36
53.39+47.39-53.21-47.21
2.53.12+4.6.87-3.8.40
5.7.77-7.150+49.25+15.42
\(a,17.93+116.83+17.23\)
\(=17.\left(93+23\right)+116.83\)
\(=116.\left(17+83\right)\)
\(=116.100\)
\(=11600\)
\(b,19.27+47.81+19.20\)
\(=19.\left(27+20\right)+47.81\)
\(=47.\left(19+81\right)\)
\(=47.100\)
\(=4700\)
\(c,87.23+13.93+70.87\)
\(=87.\left(23+70\right)+13.93\)
\(=93.\left(87+13\right)\)
\(=93.100\)
\(=9300\)
\(d,78.31+78.24+78.17+22.72\)
\(=78.\left(31+24+17\right)+22.72\)
\(=72.\left(78+22\right)\)
\(=78.100\)
\(=7800\)
Tính
53 . 39 + 47.39 +53.21+47.21
2.53.12+ 4.6.87 - 3. 8 .40
5.7.77 - 7.60 + 49.25 - 15.42
Ai làm nhanh mình tick nhé
53 x 39 + 47 x 39 + 53 x 21 + 47 x 21
= 39 x (53 + 47) + 21 x (53 + 47)
= 39 x 100 + 21 x 100
= 100 x (39 + 21)
= 100 x 40
= 4000
2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
= 1272 + 2088 - 960
= 3360 - 960
= 2400
5 x 7 x 77 - 7 x 60 + 49 x 25 - 15 x 42
= 2695 - 420 + 1225 - 630
= 2275 + 595
= 2870
Học tốt!!!
Help me ! Tính nhanh
53.39+47.39-53.21-47.21
5.7.77 - 7.60 + 49.25 - 15.42
Tớ sẽ tick đúng nhé
to se giai cho ban cau dau
39.(53+47)-21.(53+47)
chắc đến đây cậu biết phân tích ra rồi chứ
Tính nhanh:
a, 2.53.12+4.6.87-3.8.40
b,5.7.77-7.60+49.25-15.42
b,5.7.77-7.60+49.25-15.42
=35.77-35.12+35.35-35.18
=35(77-12-35-18)
=35.12
=420
tick nha
Ngồi bấm máy tính mà làm sao chậm đc!! =)) Nguyen Huu The
a) 2.53.12+4.6.87-3.8.40
= (2.12).53+(4.6).87-(3.8).40
= 24.53+24.87-24.40
= 24.(87+53)-24.40
= 24. 140-24.40
= 24.(140-40)
= 24.100
= 2400
b) tịt