Giải giúp mik câu 5 vs ạ, cảm ơn ạ
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C5:
nC2H5OH = 8,2 / 46 = 0,2 (mol)
C2H5OH + 3O2-- (t^o)-- > 2CO2 + 3H2O
VCO2 = 0,4 . 22,4 = 8,96 (l)
VO2 = 0,6.22,4=13,44 (l)
1 bỏ so
-In order to V(inf): Để làm gì
3 -So as to V(inf): Để làm gì
6 me->her
-Could/can/Will+V(inf)
-Help+O+V/to V
11 ..... me where the nearest post office is?
-Can/could+S+V+wh-questions+S+V?
14 -Shall+S+V(inf)?
17 ........ going to help him revise his lessons
-"be" going to V(inf): Sẽ làm gì( mang tính chắc chắn)
18 -Would+S+love/like+to V/N?
19 -Let's+V(inf)
= Shall+we+V(inf)?
20 -Trong ngữ cảnh này "to V" được dùng với nghĩa "để làm gì"
*Inf: Infinitive
3:
#include <bits/stdc++.h>
using namespace std;
double x,y;
int main()
{
cin>>x>>y;
cout<<fixed<<setprecision(2)<<sqrt(x*x+y*y);
return 0;
}
Bn ơi bn viết r chụp lên đc k ạ ? Mik k định dạng đc ý
1 are
2 am
3 is
4 are
5 are
6 are
7 is
8 is
9 is
10 are
IV
1 is writing
2 are losing
3 is having
4 is staying
5 am not lying
6 is always using
7 are having
8 Are you playing
9 are not touching
10 Is - listening
11 Is- winning
12 am not staying
13 is not working
14 is not reading
15 isn't raining
16 am not listening
17 Are they making
18 Are you doing
19 Is - sitting
20 is - doing
21 are-putting
22 are-wearing
23 is-studying
2, am
3, is
4,are
5,are
6,are
7,is
8,is
9,is
10,are
IV
1,2,7 OK
3,is having
4,has stayed
5,am not lying
6,always uses
8,Are-playing
9,not to touch
10,Is-listening
11,Are-winning
12,am not staying
13,isn't working
14,isn't reading
15,isn't raining
16,am not listening
17,Are-making
18,Are-doing
19,Is-sitting
20,is-doing
21,do-putting
22,do-wear
23,is-studying
4.2:
a: x^2-x+1=x^2-x+1/4+3/4
=(x-1/2)^2+3/4>=3/4>0 với mọi x
=>x^2-x+1 ko có nghiệm
b: 3x-x^2-4
=-(x^2-3x+4)
=-(x^2-3x+9/4+7/4)
=-(x-3/2)^2-7/4<=-7/4<0 với mọi x
=>3x-x^2-4 ko có nghiệm
5:
a: x^2+y^2=25
x^2-y^2=7
=>x^2=(25+7)/2=16 và y^2=16-7=9
x^4+y^4=(x^2)^2+(y^2)^2
=16^2+9^2
=256+81
=337
b: x^2+y^2=(x+y)^2-2xy
=1^2-2*(-6)
=1+12=13
x^3+y^3=(x+y)^3-3xy(x+y)
=1^3-3*1*(-6)
=1+18=19
Bài cuối mình không thấy rõ đề nhưng mình đoán là thế này bạn nhé.
2 do
3 usually buy
4 press
5 enjoy
6 has
7 goes
8 gets
9 eat
10 doesn't study
11 doesn't eat
12 doesn't water
13 don't go
14 doesn't eat - is
15 Do - go
16 Do - agree
17 Do you have
18 Do you often eat
19 Does - start
20 does he come
21 does - work
22 does
23 does - do
24 does- go