6 + 4 = 210
9 + 2 = 711
8 + 5 = 313
5 + 2 = 37
\(\Rightarrow\) 7+ 6 =???
Những câu hỏi liên quan
Đây là bài toán dành cho thiên tài toán học mà tôi tìm được trên Google.
6 + 4 = 210
9 + 2 = 711
8 + 5 = 313
5 + 2 = 7
15 + 3 = 1218
➤ ? + ?? = 123.
? và ?? là bao nhiêu và tại sao?
Xem thêm câu trả lời
Hoàn thành chuyển đổi sau: (1) (2) (3) (4) (5) (6) (7)FeS_2rightarrow Arightarrow Brightarrow H_2SO_4rightarrow Arightarrow Drightarrow Crightarrow A (8) downarrow (9) downarrow C Erightarrow BaSO_4 (10)
Đọc tiếp
Hoàn thành chuyển đổi sau:
(1) (2) (3) (4) (5) (6) (7)
\(FeS_2\rightarrow A\rightarrow B\rightarrow H_2SO_4\rightarrow A\rightarrow D\rightarrow C\rightarrow A\)
(8) \(\downarrow\) (9) \(\downarrow\)
\(C\) \(E\rightarrow BaSO_4\)
(10)
1) \(4FeS_2+11O_2\rightarrow8SO_2+2Fe_2O_3\)
2) \(2SO_2+O_2\rightarrow2SO_3\)
3) \(SO_3+H_2O\rightarrow H_2SO_4\)
4) \(H_2SO_4+K_2SO_3\rightarrow K_2SO_4+H_2O+SO_2\uparrow\)
5) \(SO_2+Na_2O\rightarrow Na_2SO_3\)
6) \(Na_2SO_3+BaS\rightarrow Na_2S+BaSO_3\downarrow\)
7) \(BaSO_3\rightarrow BaO+SO_2\uparrow\)
8) \(SO_2+Ba\left(OH\right)_2\rightarrow BaSO_3+H_2O\)
9) \(H_2SO_4+Na_2SO_3\rightarrow Na_2SO_4+SO_2+H_2O\)
10) \(Na_2SO_4+BaCl_2\rightarrow2NaCl+BaSO_4\)
Đúng 2
Bình luận (6)
27 tháng 4 2022 lúc 17:32
Hoàn thành các pt phản ứng sau:1. CH_4+Cl_2rightarrow2.C_6H_6+Br_2rightarrow3.C_6H_6+Cl_2rightarrow4.CH_3COOH+CaCO_3rightarrow5.left(RCOOright)_3C_3H_5+NaOHrightarrow6.CaCO_3+CO_2+H_2Orightarrow7.NaHCO_3rightarrowleft(t^oright)8.NaOH+SiO_2rightarrow9.NaHCO_3+HClrightarrow10.Cl_2+H_2Orightarrow11.CH_3COOC_2H_5+NaOHrightarrow12.C_6H_6+H_2rightarrow13.left(RCOOright)_3C_3H_5+H_2Orightarrow14.left(C_6H_{10}O_5right)n+H_2Orightarrow15.CH_3COONa+NaOHrightarrow16.Caleft(HCO_3right)_2underrightarrow{t^o...
Đọc tiếp
Hoàn thành các pt phản ứng sau:
1. \(CH_4+Cl_2\rightarrow\)
2.\(C_6H_6+Br_2\rightarrow\)
3.\(C_6H_6+Cl_2\rightarrow\)
4.\(CH_3COOH+CaCO_3\rightarrow\)
5.\(\left(RCOO\right)_3C_3H_5+NaOH\rightarrow\)
6.\(CaCO_3+CO_2+H_2O\rightarrow\)
7.\(NaHCO_3\rightarrow\left(t^o\right)\)
8.\(NaOH+SiO_2\rightarrow\)
9.\(NaHCO_3+HCl\rightarrow\)
10.\(Cl_2+H_2O\rightarrow\)
11.\(CH_3COOC_2H_5+NaOH\rightarrow\)
12.\(C_6H_6+H_2\rightarrow\)
13.\(\left(RCOO\right)_3C_3H_5+H_2O\rightarrow\)
14.\(\left(C_6H_{10}O_5\right)n+H_2O\rightarrow\)
15.\(CH_3COONa+NaOH\rightarrow\)
16.\(Ca\left(HCO_3\right)_2\underrightarrow{t^o}\)
17.\(MnO_2+HCl\rightarrow\)
18.\(NaHCO_3+NaOH\rightarrow\)
19.\(C_4H_{10}+O_2\underrightarrow{men}\)
20.\(NaOH+Cl_2\rightarrow\)
21.\(CH_3COOC_2H_5+H_2O\underrightarrow{t^o}\)
\(1,CH_4+Cl_2\underrightarrow{\text{ánh sáng}}CH_3Cl\\ 2,C_6H_6+Br_2\xrightarrow[t^o]{Fe}C_6H_5Br\\ 3,C_6H_6+Cl_2\underrightarrow{\text{ánh sáng}}C_6H_5Cl\\ 4,2CH_3COOH+CaCO_3\rightarrow\left(CH_3COO\right)_2Ca+CO_2\uparrow+H_2O\\ 5,\left(RCOO\right)_3C_3H_5+3NaOH\rightarrow3RCOONa+C_3H_5\left(OH\right)_3\\ 6,CaCO_3+CO_2+H_2O\rightarrow Ca\left(HCO_3\right)_2\\ 7,2NaHCO_3\underrightarrow{t^o}Na_2CO_3+CO_2\uparrow+H_2O\\ 8,NaOH+SiO_2\underrightarrow{t^o}Na_2SiO_3+H_2O\)
\(9,NaHCO_3+HCl\rightarrow NaCl+CO_2\uparrow+H_2O\\ 10,Cl_2+H_2O⇌HCl+HClO\\ 11,CH_3COOC_2H_5+NaOH\rightarrow CH_3COONa+C_2H_5OH\\ 12,C_6H_6+3H_2\xrightarrow[t^o]{Ni}C_6H_{12}\\ 13,\left(RCOO\right)_3C_3H_5+3H_2O\rightarrow3RCOOH+C_3H_5\left(OH\right)_3\\ 14,\left(-C_6H_{10}O_5-\right)_n+nH_2O\rightarrow nC_6H_{12}O_6\\ 15,CH_3COONa+NaOH\underrightarrow{t^o}CH_4\uparrow+Na_2CO_3\\16, Ca\left(HCO_3\right)\underrightarrow{t^o}CaCO_3+CO_2\uparrow+H_2O\)
\(17,MnO_2+4HCl\rightarrow MnCl_2+Cl_2\uparrow+2H_2O\\ 18,NaHCO_3+NaOH\rightarrow Na_2CO_3+H_2O\\ 19,2C_4H_{10}+5O_2\xrightarrow[men,xt]{t^o}4CH_3COOH+2H_2O\\ 20,2NaOH+Cl_2\rightarrow NaCl+NaClO+H_2O\\ 21,CH_3COOC_2H_5+H_2O\underrightarrow{t^o}CH_3COOH+C_2H_5OH\)
Đúng 3
Bình luận (0)
1) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{-6n^5+3n^3-1}{n^4-8n}\)
2) tính \(\lim\limits_{n\rightarrow\infty}\dfrac{-5n^7+8n^5-n}{5n^6-2n}\)
\(\lim\limits_{x\rightarrow-\infty}\dfrac{\left(2-x^4\right)\left(3x^5-1\right)}{7+9x-x^6}\)
Lời giải:\(\lim\limits_{x\to -\infty}\frac{(2-x^4)(3x^5-1)}{7+9x-x^6}=\lim\limits_{x\to -\infty}\frac{(\frac{2}{x}-x^3)(3-\frac{1}{x^5})}{\frac{7}{x^6}+\frac{9}{x^5}-1}\)
Ta thấy:
\(\lim\limits_{x\to -\infty}(\frac{2}{x}-x^3)=+\infty \)
\(\lim\limits_{x\to -\infty}\frac{3-\frac{1}{x^5}}{\frac{7}{x^6}+\frac{9}{x^5}-1}=\frac{3}{-1}=-3<0\)
\(\Rightarrow \lim\limits_{x\to -\infty}\frac{(2-x^4)(3x^5-1)}{7+9x-x^6}=-\infty \)
Đúng 1
Bình luận (0)
Tính:
1) 3/4 - [(-3/5) - (1/12 +2/4)]
2) -6/7 . 21/12
3) (-5) . -6/20
4) -31/36 : 37/-72
5) (-5/17) : (-15)
\(\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{2}{4}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{6}{12}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\dfrac{7}{12}\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{36}{60}\right)-\dfrac{35}{60}\right]\\ =\dfrac{3}{4}-\left(-\dfrac{71}{60}\right)\\ =\dfrac{3}{4}+\dfrac{71}{60}\\ =\dfrac{35}{60}+\dfrac{71}{60}\\ =\dfrac{106}{60}\\ =\dfrac{53}{30}\)
__
\(-\dfrac{6}{7}.\dfrac{21}{12}\\ =-\dfrac{126}{84}\\ =-\dfrac{63}{42}\\ =-\dfrac{31}{14}\)
__
\(\left(-5\right).\left(-\dfrac{6}{20}\right)\\ =\dfrac{\left(-5\right).\left(-6\right)}{20}\\ =\dfrac{30}{20}\\ =\dfrac{3}{2}\)
__
\(-\dfrac{31}{36}:\left(-\dfrac{37}{72}\right)\\ =-\dfrac{31}{36}.\left(-\dfrac{72}{37}\right)\\ =\dfrac{2322}{1332}\)
__
\(\left(-\dfrac{5}{17}\right):\left(-15\right)\\ =\left(-\dfrac{5}{17}\right).\left(-\dfrac{1}{15}\right)\\ =\dfrac{5}{255}\\ =\dfrac{1}{51}\)
Đúng 2
Bình luận (0)
\(\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{2}{4}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\left(\dfrac{1}{12}+\dfrac{6}{12}\right)\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{3}{5}\right)-\dfrac{7}{12}\right]\\ =\dfrac{3}{4}-\left[\left(-\dfrac{36}{60}\right)-\dfrac{35}{60}\right]\\ =\dfrac{3}{4}-\left(-\dfrac{71}{60}\right)\\ =\dfrac{3}{4}+\dfrac{71}{60}\\ =\dfrac{35}{60}+\dfrac{71}{60}\\ =\dfrac{106}{60}\\ =\dfrac{53}{30}\)
__
\(-\dfrac{6}{7}.\dfrac{21}{12}\\ =-\dfrac{126}{84}\\ =-\dfrac{63}{42}\\ =-\dfrac{31}{14}\)
__
\(\left(-5\right).\left(-\dfrac{6}{20}\right)\\ =\dfrac{\left(-5\right).\left(-6\right)}{20}\\ =\dfrac{30}{20}\\ =\dfrac{3}{2}\)
__________
Đúng 2
Bình luận (4)
6+4=210 9+2=711 8+5=37 vay 7+6=????
Bài 1: Tính :4/5 x 6/7 2/9 x 1/2 1/2 x 8/37/9 x 6/5 8/7 x 5/9 10/11 x 22/15Bài 2: Rút gọn rồi tính:2/6 x 5/3 11/9 x 5/10 3/9 x 6/84/9 x 12/16 25/15 x 6/7 6/10 x 15/20
Đọc tiếp
Bài 1: Tính :
4/5 x 6/7 2/9 x 1/2 1/2 x 8/3
7/9 x 6/5 8/7 x 5/9 10/11 x 22/15
Bài 2: Rút gọn rồi tính:
2/6 x 5/3 11/9 x 5/10 3/9 x 6/8
4/9 x 12/16 25/15 x 6/7 6/10 x 15/20
Bài 2:
a: 2/6x5/3=10/18=5/9
b: 11/9x5/10=55/90=11/18
c: 3/9x6/8=1/3x3/4=1/4
d: 4/9x12/16=48/144=1/3
e: 25/15x6/7=5/3x6/7=30/21=10/7
f: 6/10x15/20=90/200=9/20
Đúng 1
Bình luận (0)
Bài 1
4/5 x 6/7= 24/35
2/9 x 1/2= 2/18= 1/9
1/2 x 8/3= 8/6= 4/3
7/9 x 6/5= 42/45= 14/15
8/7 x 5/9= 40/63
10/11 x 22/15= 220/165= 4/3
Bài 2
2/6 x 5/3= 1/3 x 5/3=5/9
11/9 x 5/10= 11/9 x 1/2= 11/18
3/9 x 6/8= 1/3 x 3/4 =3/12= 1/4
4/9 x 12/16= 4/9 x 3/4= 12/36= 1/3
25/15 x 6/7= 5/3 x 6/7= 30/21= 10/7
6/10 x 15/20= 3/5 x 3/4= 9/20
Đúng 0
Bình luận (0)
bài 1
4/5 x 6/7 = 24/35
2/9 x 1/2 = 1/9
1/2 x 8/3 = 4/3
7/9 x 6/5 = 14/15
8/7 x 5/9 = 14/15
8/7 x 5/9 = 40/63
10/11 x 22/15 = 4/3
Đúng 0
Bình luận (0)
lam ho 1)A) 1- (5va4/9 +X -7va 7/18): 15va3/4=0
; B)X +1/2+1/4+1/8+1/16+1/32+1/64+1/128
---------------------------------------------------------- =9/2
1/3*4+1/4*5+1/5*6+1/6*7+1/7*8+1/8*9
2)
a)A=
5+8/17 +8/37
------------------
4+4/17+4/37
B)B=7/12+7/6+7/12+...+7/9900