|-105| - |-25| + |15| - |5|
53.(-7)+47.(-7)+14.(-25)-4.(-25)
a.14×99
b.7989×997
c.15373×9998
d.42×53+47×156×47×114
e.5×77×7-7×60+49×25-15×42
a) 1 386
b) 7 965 033
c) 153 699 254
d) 1 846 390 458
e) 2 870
a.14×99
b.7989×997
c.15373×9998
d.42×53+47×156×47×114
e.5×77×7-7×60+49×25-15×42
a) 1 386
b) 7 965 033
c) 153 699 254
d) 1 846 390 458
e) 2 870
\(\left(a\right)14.99=1386\)
\(\left(b\right)7989x997=7965033\)
\(\left(c\right)15373.9998=153699254\)
\(\left(d\right)42.53+47.156.47.114=1846390458\)
\(\left(e\right)5.77.7-7.60+49.25-15.42=2870\)
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*25-15*42
53x39+47x39-53x21-47x21
=39x ( 53+47) - 21x(53+47)
=39 x100 - 21x100
= 100x(39-21)
=100x18
=1800
2x53x12 +4x6x87 - 3x8x40
= (2x12)x53 + (4x16)x87 - (3x8) x40
= 24x53 + 24x87 + 24x40
= 24( 53+87+40)
= 24x180
=4320
a,53*39+47*39-53*21-47*21
=39*[53+47]-21*[53+47]
=39*100-21*100
=3900-2100
=1800
b,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*[53+87-40]
=24*100
=2400
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
bài1
1) (-4/15)(-25/8)
2) 5/-14(-7/10)
3) -15/4(-16/25
4) 15(13/10
5) -21/9*-6/14
1)\(\dfrac{5}{6}\)
2)\(\dfrac{1}{4}\)
3)\(\dfrac{12}{5}\)
4)\(\dfrac{39}{2}\)
5)\(1\)
42. 53 + 47. 156 - 47. 114
53. ( 51 + 4 ) + 53. ( 49 + 96 ) + 53
42. ( 15 + 96 ) + 6. ( 25 +4 ). 7
1, 42 x 53 + 47 x 156 - 47 x 114
= 42 x 53 + 47 x ( 156 - 114 )
= 42 x 53 + 47 x 42
= 42 x ( 53 + 47 )
= 42 x 100
= 4200
2, 53 x ( 51 + 4 ) + 53 x ( 49 + 96 ) + 53
= 53 x 51 + 53 x 4 + 53 x 49 + 53 x 96
= 53 x ( 51 + 49 ) + 53 x ( 96 + 4 ) + 53
= 53 x 100 + 53 x 100 + 53
= 5300 + 5300 + 53
= 10653
3, 42 x ( 15 + 96 ) + 6 x ( 25 + 4 ) x 7
= 42 x 15 + 42 x 96 + 42 x 25 + 42 x 4
= 42 x ( 15 + 25 ) + 42 x ( 96 + 4 )
= 42 x 40 + 42 x 100
= 42 x ( 100 + 40 )
= 42 x 140
= 5880
Tk mk nha !! ~
42. 53 + 47. 156 - 47. 114 = 42.53 +47.(156-114)
=42.53 +47. 42
= 42(53+47)
= 42.100 = 4200
53. ( 51 + 4 ) + 53. ( 49 + 96 ) + 53 = 53(51+4+49+96+1)
= 53. 201 = 10653
42. ( 15 + 96 ) + 6. ( 25 +4 ). 7 = 42. ( 15 + 96 ) + 42(25+4)
= 42(15+96+25+4)
= 42. 140 = 5880
mk lm xong rồi add friend nha
TRẢ LỜI:
A/ 42 . 53 + 47 . 156 - 47 . 114
=2226 + 7332 - 5358
=9558 - 5358
=4200
B/ 53 . (51 + 4) + 53 .(49 + 96) + 53
=53 . 51 + 53 . 4+ 53. 49+ 53. 96+ 53
=2703 + 212 +2597 +5088 + 53
=2924 + 7738
=10662
C/ 42.(15+96)+6.(25+4).7
=42. 15+42. 96+6 . 25+6.4.7
=630+4032+150+168
=4980
CHÚC BN HOK TỐT
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
Bài 4 : Tính nhanh :
a: 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21
b: 2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
c: 5 x 7 x 77 - 7 x 60 + 49 x 25 - 15 x 42
Bài 5 : Tìm x , biết :
a: x : [( 1800 + 600 ) : 30 ] = 560 : ( 315 - 35 )
b: [( 250 - 25 ) : 15 ] : x = ( 450 - 60 ) : 130
Bạn dùng tính chất phân phối, giao hoán để làm nhé
1) a) 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 6
= 3900 - 126
= 3774
b) 2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
= 1272 + 2088 - 960
= 3360 - 960
= 2400
c) 5 x 7 x 77 - 7 x 60 + 47 x 25 - 15 x 42
= 2695 - 420 + 1175 - 630
= 2275 + 545
= 2820
2) a) x : [(1800 + 600) : 30] = 560 : (315 - 35)
x : (2400 : 30) = 560 : 280
x : 80 = 2
x = 2 x 80
=> x = 160
b) [(250 - 25) : 15] : x = (450 - 60) : 130
225 : 15 : x = 390 : 130
15 : x = 3
x = 15 : 3
=> x = 5
Học tốt!!!
a 12 – 34 b 23 – 47 c 31 – 23 d 9 – 5 e 4 – 15 25 f 23 13 17 57 g 4 . 9 6 . 12 – 7 h 14 6 19 14 19 i 56 – 8. 27 7 j 8 5 . 2 – 3 6 k 4 . 3 125 . 25 8 l 9 6 . 3 – 4 7 m 45. 18 – 15 – 18. 45 – 15
Tách từng câu ra giùm, như này ai giải nổi:)))))
1. Tính
a, 1+7+8+15+23+...+160
b, 17+4+5+9+19+...+60+9
c, 78*3+78*24+78*17*22*72
d, 53*39+47*39+47-53*21-47*21
e, 2*53*12+4*6*87-3*8*40
g, 5*7*77-7*60+49*25-15*42
h, 1*2+2*3+3*4+...+2016*2017