Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
2,
a) \(315-\left(135-x\right)=215\)
\(\Rightarrow135-x=315-215\)
\(\Rightarrow135-x=100\)
\(\Rightarrow x=135-100\)
\(\Rightarrow x=35\)
b) \(x-320:32=25\cdot16\)
\(\Rightarrow x-10=5^2\cdot4^2\)
\(\Rightarrow x-10=20^2\)
\(\Rightarrow x-10=400\)
\(\Rightarrow x=410\)
c) \(3\cdot x-2018:2=23\)
\(=3\cdot x-1009=23\)
\(\Rightarrow3\cdot x=1032\)
\(\Rightarrow x=1032:3\)
\(\Rightarrow x=344\)
d) \(280-9\cdot x-x=80\)
\(\Rightarrow280-x\cdot\left(9+1\right)=80\)
\(\Rightarrow280-10\cdot x=80\)
\(\Rightarrow10\cdot x=280-80\)
\(\Rightarrow10\cdot x=200\)
\(\Rightarrow x=20\)
e) \(38\cdot x-12\cdot x-x\cdot16=40\)
\(\Rightarrow x\cdot\left(38-12-16\right)=40\)
\(\Rightarrow x\cdot10=40\)
\(\Rightarrow x=40:10\)
\(\Rightarrow x=4\)
11+12+13+14+15+16+17+18+19+...+89+88+87+86+85+84+83+82
=( 11 + 89 )+(12+88)+(13+87)+(14+86)+(15+85)+(16+84)+(17+83)+(18+82)+19
=100+100+100+100+100+100+100+100+19
=800+19
=819
a,(17-414)-(586-83)
=17-414-586+83
=(17+83)+(-414-586)
=100+(-1000)
=-900
b,29.(-13)+27.(-29)+(-140).(-29)
=(-29).(-1).(-13)+27.(-29)+(-140).(-29)
=(-29).13+27.(-29)+(-140).(-29)
=(-29).(13+27-140)
=(-29).(-100)
=2900
1. -86 + ( -14)
= -86 - 14
= -100
2. 123 + ( -36)
= 123 - 36
= 87
3. ( -44) - ( -66)
= -44 + 66
= 22
4. -82 + (-28)
= -82 - 28
= -110
5. 83 + ( -17)
= 83 - 17
= 66
Các bài khác làm tương tự nha bạn
1/ (-86)+(-14)=-86-14=-100
2/123+(-36)=123-36=87
3/(-44)-(-66)=-44+66=22
4/-82+(-28)=-82-28=-110
5/83+(-17)=83-17=66
6/(-83)-33=(-83)+(-33)=-116
7/ 73+(-24)=73-24=49
8/84+(-48)=84-48=36
9/-72-82=-72+(-82)=-154
10/-97-82=-97+(-82)=-179
11/19+(-92)=19-92=-73
12/38-28=10
13/13+(-27)=13-27=-14
14/-85+29=-85-(-29)=-114
15/-84-(-27)=-84+27=-57
16/-23+78=-23-(-78)=-101
17/93+(-29)=93-29=64
18/-74-83=-74+(-83)=-157
19/-183+83=-183-(-83)=-266
20/849-(-3832)=849+3832=4681
Có gì sai mong bạn sửa giúp mình nhé!
\(\Leftrightarrow\dfrac{x+100}{86}+\dfrac{x+100}{85}+\dfrac{x+100}{84}+\dfrac{x+100}{83}=0\)
=>x+100=0
hay x=-100
13 + 21.5 - (198 : 11 - 8)
= 13 + 105 - 10
= 108
272 : 16 - 5 +4 (30 - 5 - 255 : 17)
= 17 - 5 + 4. ( 30 - 5 - 15 )
= 16 . 10
= 160
15.24 - 14.5 (145 : 5 - 27)
= 360 - 70 ( 29 - 27 )
= 290 . 2
= 580
18.3 - 18.2 + 3 (51 : 17)
= 54 - 36 + 3 . 3
= 54 - 36 + 9
= 27
(64 + 115 + 36) - 25.8
= 215 - 200
= 15
15.8 - (17 - 30 + 83) - 144 : 6
= 120 - 70 - 24
= 26
250 : 50 - (46 - 75 + 54) : 5
= 5 - 25 : 5
= 5 - 5
= 0
13 (17 - 95 + 83) : 5 - 18 : 9
= 13. 5 : 5 - 2
= 65 : 5 - 2
= 13 - 2
= 11
140 - 180(47 - 90 + 43) + 7
= 140 - 180 . 0 + 7
= 140 + 7
= 147
24 (15 + 30 + 85 - 120):10
= 24. 10 : 10
= 240 : 10
= 24
27 + 73 - 30 : (25 -10)
= 27 + 73 - 30 : 15
= 27 + 73 - 2
= 98
18 - 4 (27 - 90 + 73) : 10
= 18 - 4. 10 : 10
= 18 - 40 : 10
= 18 - 4
= 14
Bài 2: Tính
140 - [ 25 : (4 mũ 2 - 11) + 4 ]
= 140 - [25 : (16 - 11) + 4 ]
= 140 - [ 25 : 5 + 4 ]
= 140 - [ 5 + 4]
= 140 - 9
= 131
\(\dfrac{x-13}{87}+\dfrac{x-27}{73}+\dfrac{x-67}{83}+\dfrac{x-73}{27}=4\)
<=>\(\dfrac{x-13}{87}-1+\dfrac{x-27}{73}-1+\dfrac{x-67}{83}-1+\dfrac{x-73}{27}-1=0\)
<=>\(\dfrac{x-100}{87}+\dfrac{x-100}{73}+\dfrac{x-100}{83}+\dfrac{x-100}{27}=0\)
<=>\(\left(x-100\right)\left(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}\right)=0\)
Do \(\dfrac{1}{87}+\dfrac{1}{73}+\dfrac{1}{83}+\dfrac{1}{27}>0\)
=>x-100=0
<=>x=100
\(83\times14+27\times17+83\times13\)
\(=83\times\left(14+13\right)+27\times17\)
\(=83\times27+27\times17\)
\(=\left(83+17\right)\times27\)
\(=100\times27\)
\(=2700\)
Chúc bạn học tốt
83×14+27×17+83×13
=83×(14+13)+27×17=83×(14+13)+27×17
=83×27+27×17=83×27+27×17
=(83+17)×27=(83+17)×27
=100×27=100×27
=2700=2700
Chúc bạn học tốt