Tính nhanh: 35 x 49+51 x 36
35 x 49 + 51 x 36 = 35 x 49 + 51 x ( 35+1) =35 x 49 + 51 x 35 + 51 = 35 x ( 49 + 51 ) + 51 = 35 x 100 + 51 = 3500+51 = 3551
=(36-1)x49+51x36
=36x49-1x49+51x36
=36x49-49+51x36
=36x(49+51)-49
=36x100-49
=3600-49
=3551
Tính nhanh
a : 2459 - ( 400 + 459 )
b : 435 x 25 + 76 x 435 - 435
c : 35 x 49 + 51 x 36
a) \(\text{2459 - (400 + 459)}\)
\(\text{= 2459 - 859}\)
\(\text{= 1600}\)
b) \(435\times25+76\times435-435\)
\(=435\times\left(25+76-1\right)\)
\(=435\times100\)
\(=43500\)
c) \(35\times49+51\times36\)
\(=35\times49+51\times\left(35+1\right)\)
\(=35\times49+51\times35+51\)
\(=35\times\left(49+51\right)+51\)
\(=35\times100+51\)
\(=3500+51\)
\(=3551\)
a) 2459 - (400 + 459)
= 2459 - 400 - 459
= (2459 - 459) - 400
= 2400 - 400
= 2000
b) 435 x 25 + 76 x 435 - 435
= 435 x (25 + 76 - 1)
= 435 x 100
= 43500
c) 35 x 49 + 51 x 36
= 1715 + 1836
= 3551
Tính nhanh :
35×49+51×36
=3551 nha mn'
mong mn ửng hộ cho tũn một tích
35*49+51*36
=35*49+51*35+51
=35*(49+51)+51
=3500+51
3551
Hok tot
1,Tính nhanh
a, 568 + 568 x 135 - 568 x 36
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
a, 568 + 568 x 135 - 568 x 36
= 568 x ( 1 + 135 - 36)
= 568 x 100
56 800
b, 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
= 49 x ( 17 + 37) + 54 x ( 26 + 25 )
= 49 x 54 + 54 x 51
= 54 x ( 49 + 51)
= 54 x 100
= 5 400
c, 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
= ( 2 x 35) x ( 7 x 5) + ( 10 x 7) x 25 + 20 x 70
= 70 x 35 + 70 x 25 + 20 x 70
= 70 x ( 35 + 25 + 20)
= 70 x 80
= 5 600
a) 568 + 568 x 135 - 568 x 36
= 568 x ( 1+1+135-1-36 )
=568 x 100
=5680
b) 17 x 49 + 49 x 37 + 54 x 26 + 54 x 25
= 49 x ( 17 + 37 ) + 54 x ( 26 + 25 )
= 49 x 54 + 54 x 51
= 54 x ( 49 + 51 )
= 54 x 100
= 5400
c) 14 x 35 x 5 + 10 x 25 x 7 + 20 x 70
= 70 x 35 + 10 x 25 x 7+ 20 x 70
= 70 x 35 + 250 x 7 + 20 x 70
= 70 x 35 + 70 x 25 + 20 x 70
= 70 x (35+25+20)
= 70 x 80
= 5600
đề 2 tính nhanh
a) 2459 - ( 400 + 459 ) b) 435 x 25 + 76 x 435 c) 35x 49 + 51 x 35
a) 2459 - ( 400 + 459 )
= ( 2459 - 459 ) - 400
= 2000 - 400
= 1600
b) 435 x 25 + 75 x 435
= 435 x ( 75 + 25 )
= 435 x 100
= 43 500
c) 35 x 49 + 51 x 35
= 35 x ( 49 + 51 )
= 35 x 100
= 3500
Tính hợp lý:
a) 73 x 49 + 73 x 51
b) 22344 x 36 + 44688 x 82
c) 3 x 18 x 12 + 4 x 82 x 9
d ) 36 x 28 + 36 x 82 + 64 x 69 + 64 x 41
NHANH LÊN NHÉ CÁC BẠN MÌNH CHỜ ĐẤY
a) 73 x 49 + 73 x 51 b) 22344 x 36 + 44688 x 82 c) 3 x 18 x 12 + 4 x 82 x 9 d) 36 x 28 + 36 x 82 +64 x 69 + 64 x 41
= 73 x (49 + 51) =804384 + 3664416 = 648 + 2952 = 36 x (28 + 82) + 64 x (69 + 41)
=73 x 100 =4468800 = 3600 = 36 x 110 + 64 110
=7300 = 110 x (36 x 64)
= 110 x 100
= 11000
Tính nhanh
91 x 51 + 49 x 163 - 49 x 72
91 x 51 + 49 x 163 - 49 x 72
= 91 x 51 + 49 x ( 163 - 72 )
= 91 x 51 + 49 x 91
= 91 x ( 51 + 49 )
= 91 x 100
= 9100
91x51 + 49x163-49x72
=91x51+49x( 163-72)
=91x51+49x91
=91x(51+49)
=91x100
=9100
91 x 51 + 49 x 163 - 49 x 72
= 91 x 51 + 49 x ( 163 - 72 )
= 91 x 51 + 49 x 91
= 91 x ( 51 + 49 )
= 91 x 100
= 9100
1 tính nhanh
13 x 58 x 4 + 32 x 36 x2 +52 x 10
14 x 35 x 5 + 10x 25 x 7 +20 x 70
24 x (15 +49) +12x (50+42)
Bài 1 :Tính một cách hợp lý
1) 39×51+39×49
2) 50×62+100×19
3) 49×53-51-49×53+69
4) 179-59×78-79+59
5) 35×(41-12)+41×(37-35)
Bài 2: thu gọn phép tính
a) 51-x +3x - 16
b) 75- 2x - 25 - x
c) x - 76 + 4x - 24
d) (2x - 17) - (51 - 6x)
e) (10a - 5) -(7a+15)
1) 39×51+39×49=39x(51+49)=39x100=3900
2. phân tích 100 thành 50 r lm như câu 1
1. = 39 x (51 + 49)
= 39 x 100
= 3900
2. = 50 x 2 x 31 + 100 x 19
= 100 x 31 + 100 x 19
= 100 x (31 + 19)
= 100 x 50
= 5000