làm hộ mình bài 1,2 ạ
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DT
Đỗ Thanh Hải
CTVVIP
9 tháng 7 2021
1 She failed to do everything she was supposed to do
2 There is no likelihood that anyone will apply for this post
3 He succeeded in finishing the English test in time
4 There is no likelihood that the situation will improve in the near future
5 There is a chance that you will get what you want there
6 Don't check your answers before answering all the questions
7 I won't give an opinion before thinking this through
8 The judge will decide after hearing all the evidence
9 I won't be able to have a holiday until I save enough money
10 There is little likelihood that my sister will win the first prize in the singing contest
11 He made no reference of his new job when I last spoke to him
9 tháng 7 2021
1 She failed to do everything she was supposed to do
2 There is no likelihood that anyone will apply for this post
3 He succeeded in finishing the English test in time
4 There is no likelihood that the situation will improve in the near future
5 There is a chance that you will get what you want there
6 Don't check your answers before answering all the questions
7 I won't give an opinion before thinking this through
8 The judge will decide after hearing all the evidence
9 I won't be able to have a holiday until I save enough money
10 There is little likelihood that my sister will win the first prize in the singing contest
11 He made no reference of his new job when I last spoke to him
15 tháng 5 2021
Câu 2:
a) Ta có: \(-7x+21< 0\)
\(\Leftrightarrow-7x< -21\)
hay x>3
Vậy: S={x|x>3}
15 tháng 5 2021
Câu 2:
b) Ta có: x<y
nên -x>-y
\(\Leftrightarrow-x+2021>-y+2021\)
mà \(-y+2021>-y+2020\)
nên -x+2021>-y+2020
hay 2021-x>2020-y
24 tháng 5 2022
C1
A. baseball - football - volleyball - basketball - ice hockey
B. judo - gymnastics
C. skiing - ice-skating - horse-riding
18 tháng 2 2021
1) Vì x=25 thỏa mãn ĐKXĐ nên Thay x=25 vào biểu thức \(A=\dfrac{\sqrt{x}-2}{x+1}\), ta được:
\(A=\dfrac{\sqrt{25}-2}{25+1}=\dfrac{5-2}{25+1}=\dfrac{3}{26}\)
Vậy: Khi x=25 thì \(A=\dfrac{3}{26}\)
2) Ta có: \(B=\dfrac{\sqrt{x}-3}{\sqrt{x}+1}+\dfrac{2x+8\sqrt{x}-6}{x-\sqrt{x}-2}\)
\(=\dfrac{\left(\sqrt{x}-3\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}+\dfrac{2x+8\sqrt{x}-6}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{x-5\sqrt{x}+6+2x+8\sqrt{x}-6}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{3x+3\sqrt{x}}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{3\sqrt{x}\left(\sqrt{x}+1\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{3\sqrt{x}}{\sqrt{x}-2}\)
NH
0
30 tháng 3 2021
Câu IV:
1) Xét tứ giác BFEC có
\(\widehat{BFC}=\widehat{BEC}\left(=90^0\right)\)
\(\widehat{BFC}\) và \(\widehat{BEC}\) là hai góc cùng nhìn cạnh BC
Do đó: BFEC là tứ giác nội tiếp(Dấu hiệu nhận biết tứ giác nội tiếp)
hay B,F,E,C cùng nằm trên 1 đường tròn(đpcm)
Bài 2:
a: Số số hạng là \(999-1+1=999\left(số\right)\)
Tổng của dãy số là \(999\cdot\dfrac{\left(999+1\right)}{2}=999\cdot500=499500\)
b: Số số hạng là \(\dfrac{2010-10}{2}+1=\dfrac{2000}{2}+1=1001\left(số\right)\)
Tổng của dãy số là \(\left(2010+10\right)\times\dfrac{1001}{2}=1011010\)
c: Số số hạng là \(\dfrac{79-1}{3}+1=27\left(số\right)\)
Tổng của dãy số là: \(\left(79+1\right)\times\dfrac{27}{2}=27\times40=1080\)
d: Số số hạng là \(\dfrac{155-15}{2}+1=71\left(số\right)\)
Tổng của dãy số là (155+15)x71/2=6035
Bài 3:
a: 71-(33+x)=26
=>33+x=71-26=45
=>x=45-33=12
b: (x+73)-26=76
=>x+73-26=76
=>x+47=76
=>x=76-47=29
c: 45-(x+9)=6
=>x+9=45-6=39
=>x=39-9=30
d: 89-(73-x)=20
=>73-x=89-20=69
=>x=73-69=4
e: (x+7)-25=13
=>x+7=38
=>x=38-7=31
f: 198-(x+4)=120
=>x+4=198-120=78
=>x=78-4=74
m: 7x-5=16
=>7x=21
=>x=21:7=3
n: 156-2x=82
=>2x=156-82=74
=>x=74:2=37
k: 10x+65=125
=>10x=125-65=60
=>x=60:10=6
Bài 1:
a: 36+59+64
=(36+64)+59
=100+59=159
b: 123-79+77
=(123+77)-79
=200-79=121
c: \(23\cdot46+23\cdot64\)
\(=23\cdot\left(46+64\right)\)
\(=23\cdot110=2530\)
d: \(19\cdot34+19\cdot66-900\)
\(=19\cdot\left(34+66\right)-900\)
=1900-900=1000
e: \(58\cdot75+58\cdot50-58\cdot25\)
\(=58\left(75+50-25\right)\)
\(=58\cdot100=5800\)
f: \(27\cdot39+27\cdot63-2\cdot27=27\cdot\left(39+63-2\right)\)
\(=27\cdot100=2700\)
m: \(128\cdot46+128\cdot32+128\cdot22\)
\(=128\cdot\left(46+32+22\right)=128\cdot100=12800\)
n: \(66\cdot25+5\cdot66+66\cdot14+33\cdot66\)
\(=66\left(25+5+14+33\right)=66\cdot77=5082\)
k: \(12\cdot35+35\cdot182-35\cdot94\)
\(=35\cdot\left(12+182-94\right)\)
\(=35\cdot100=3500\)
h: \(35\cdot23+35\cdot41+64\cdot65\)
\(=35\cdot\left(23+41\right)+64\cdot65\)
\(=35\cdot64+64\cdot65=64\cdot100=6400\)