tính nhanh
28 x ( 231 + 64 ) + 72 x ( 230 + 70 )
231-(x-6)=1339:13
70-5.(2x-3)=45
156-(x+61)=82
6.(5x+35)=330
936-(4x+24)=72
a, \(231-\left(x-6\right)=1339:13\)
\(\Leftrightarrow231-\left(x-6\right)=103\)
\(\Leftrightarrow x-6=128\)
\(\Leftrightarrow x=134\)
Vậy .....
b, \(70-5\left(2x-3\right)=45\)
\(\Leftrightarrow5\left(2x-3\right)=25\)
\(\Leftrightarrow2x-3=5\)
\(\Leftrightarrow2x=8\)
\(\Leftrightarrow x=4\)
Vậy ....
c, \(156-\left(x+61\right)=82\)
\(\Leftrightarrow x+61=74\)
\(\Leftrightarrow x=13\)
Vậy ....
d, \(6\left(5x+35\right)=330\)
\(\Leftrightarrow5x+35=55\)
\(\Leftrightarrow5x=20\)
\(\Leftrightarrow x=4\)
Vậy ......
e, \(936-\left(4x+24\right)=72\)
\(\Leftrightarrow4x+24=864\)
\(\Leftrightarrow4x=840\)
\(\Leftrightarrow x=210\)
Vậy ...
231-(x-6)=1339:13
237-x=103
=>x=237-103=134
Vậy x=134
70-5(2x-3)=45
70-10x+15=45
=>-10x=45-15-70=-40
=>x=4
Vậy x=4
Các caau sau tương tự nhé bn
a, 231 - ( x - 6 ) = 1339 : 13
231 - ( x -6 ) = 103
x - 6 = 231 - 103 = 128
x = 128 + 6 = 134
b, 70 - 5 (2x -3 ) = 45
5 ( 2x -3 ) = 70 - 45 = 25
( 2x -3 ) = 25 : 5 = 5
2x = 5 + 3 = 8
x = 8 : 2 = 4
c, 156 - ( x + 61 ) = 82
x + 61 = 156 - 82 =74
x = 74 - 61
x = 13
d, 6 ( 5x + 35 ) = 330
5x + 35 = 330 : 6 = 55
5x = 55 - 35 = 20
x = 20 : 5 = 4
e, 936-(4x+ 24 ) = 72
4x + 24 = 936 - 72 = 864
4x = 864 - 24 = 840
x = 840 : 4 = 210
Chuc ban hoc tot nhe
Tính
1) 12.2.25+29.25+59.25
2) 25.(231+69)+72.(231+69)
3) 39.(250+87)+64.(240+97)
4) 36.28+36.82+64.69+64.41
1) 12.2.25+29.25+59.25
=24.25+29.25+59.25
=25(24+29+59)
=25.112
=2800
2) 25.(231+69)+72.(231+69)
=25.300+72.300
=300(25+72)
=300.97
=29100
3) 39.(250+87)+64.(240+97)
=39.337+64.337
=337.(39+64)
=337.103
=34711
4) 36.28+36.82+64.69+64.41
=36.(28+82)+64.(69+41)
=36.110+64.110
=110(36+64)
=110.100
=11000
Đăng từng bài thôi nha bạn.
12 x 2 x 25 + 29 x 25 + 59 x 25 = 2800
25 x ( 231 + 69 ) + 72 x ( 231 + 69 ) = 29100
39 x ( 250 + 87 ) + 64 x ( 240 + 97 ) = 34711
36 x 28 + 36 x 82 + 64 x 69 + 64 x 41 = 11000
Cho mik xin đúng nhá
tính nhanh
1) 12.2.25+29.25+59.25
2) 25.(231+69)+72.(231+69)
3) 39.(250+87)+64.(240+97)
4) 36.28+36.82+64.69+64.41
1) 12 x 2 x 25 + 29 x 25 + 59 x 25
= 24 x 25 + 29 x 25 + 59 x 25
= 25 x ( 24 + 29 + 59 )
= 25 x 112
= 2800
2) 25 x ( 231 + 69 ) + 72 x ( 231 + 69 )
= 25 x 300 + 72 x 300
= ( 25 + 72 ) x 300
= 29100
3)39 x ( 250 + 87 ) + 64 x ( 240 + 97 )
= 39 x 337 + 64 x 337
= ( 39 + 64 ) x 337
= 103 x 337
= 34711
tính nhanh
1) 12.2.25+29.25+59.25
2) 25.(231+69)+72.(231+69)
3) 39.(250+87)+64.(240+97)
4) 36.28+36.82+64.69+64.41
1) 12 x 2 x 25 + 29 x 25 + 59 x 25
= 24 x 25 + 29 x 25 + 59 x 25
= 25 x ( 24 + 29 + 59 )
= 25 x 112
= 2800
2) 25 x ( 231 + 69 ) + 72 x ( 231 + 69 )
= 25 x 300 + 72 x 300
= ( 25 + 72 ) x 300
= 29100
3)39 x ( 250 + 87 ) + 64 x ( 240 + 97 )
= 39 x 337 + 64 x 337
= ( 39 + 64 ) x 337
= 103 x 337
= 34711
1) 12 x 2 x 25 + 29 x 25 + 59 x 25
= 24 x 25 + 29 x 25 + 59 x 25
= 25 x ( 24 + 29 + 59 )
= 25 x 112
= 2800
2) 25 x ( 231 + 69 ) + 72 x ( 231 + 69 )
= 25 x 300 + 72 x 300
= ( 25 + 72 ) x 300
= 29100
3)39 x ( 250 + 87 ) + 64 x ( 240 + 97 )
= 39 x 337 + 64 x 337
= ( 39 + 64 ) x 337
= 103 x 337
= 34711
Chọn giá trị đúng với mỗi biểu thức sau:
125 - 82 + 7; 40:5 x 8; 20+70-30; 72:9 x 10
50; 60; 64; 80
125-82+7=50
40:5x8=64
20+70-30=60
72:9x10=80
a, 28(231+69)+72(231+69) b, 39(250+87)+64(240+97)
a, 28(231+69)+72(231+69)
=231+69.(28+72)
=231+69.100
=231+6900
=7131
b, 39(250+87)+64(240+97)
=39.337+64.337
=337(39+64)
=337.103
=34711
tính nhanh nhất có thể (tính thuận tiện hợp lí )36 x 70+ 70+64 =
70 x 64 mới tính nhanh được chứ 70 + 64 răng tính nhanh?
\(36.70+70.64=70\left(36+64\right)=70.100=7000\)
(Hình như sai dấu?)
36.70+70.64
= 70.( 36 + 64 )
= 70.100
= 7000
15 x ( 32 - 24 : x ) - 230 = 70
\(15\times\left(32-24\div x\right)-230=70\)
\(15\times\left(32-24\div x\right)=300\)
\(32-24\div x=20\)
\(24\div x=12\)
\(x=2\)
\(15\times\left(32-24:x\right)-230=70\)
\(15\times\left(32-24:x\right)=70+230\)
\(15\times\left(32-24:x\right)=300\)
\(32-24:x=300:15\)
\(32-24:x=20\)
\(24:x=32-20\)
\(24:x=12\)
\(x=24:12\)
\(x=2\)
\(#WendyDang\)
\(15\cdot\left(32-24:x\right)=300\)
\(32-24:x=300:15=20\)
\(24:x=32-20=12\)
\(x=24:12=2\)
tính nhanh
64 : 8 - 32 : 8
72 x 7 + 36 x 86
a.(64 - 32 ) :8 = 32 : 8 = 4
b. 36 x 2 x7 + 36 x 86
= 36 x (14 + 86)
= 36 x 100
= 3600
68:8 - 32 : 8
= ( 68 - 32): 8
= 36 : 8
= 4,5
72 x 7 + 36 x 86
= 72 x 7 + 36 x 2 x 43
= 72 x 7 + 72 x 43
= 72 x ( 7 + 43)
= 72 x 50
= 3600
a) 64 : 8 - 32 : 8
=( 64 - 32 ) : 8
= 32 : 8
= 4
b. 36 x 2 x7 + 36 x 86
= 36 x (14 + 86)
= 36 x 100
= 3600
Tính nhẩm
8 x 6 =
8 x7 =
8 x 8 =
8 x 9 =
48 : 8 =
56 : 8 =
64 : 8 =
72 : 8 =
8 x 6 = 48
8 x7 = 56
8 x 8 = 64
8 x 9 = 72
48 : 8 = 6
56 : 8 = 7
64 : 8 = 8
72 : 8 = 9