Hãy chuyển câu sau sang thể phủ định và nghi vấn.
-His students take an important exam .
-Her grandma gets up early everyday.
1/ His teacher regrets _______ him that his application for the job has been turned down.
A. tell B. to tell C. telling D. tells
2/ The workers stopped _______ a rest because they felt tired.
A. take B. to take C. taking D. took
3. At school, students usually take part in_______money for charity.
A. raised B. to raise C. raising D. raise
4. Let's__________for a walk.
A. go B. to go C. going D. went
5. Why don't you consider to visit me? I really look forward to_______you.
A. see B. seen C. seeing D. saw
6. It's impolite___________people about their salary.
A. asked B. to ask C. ask D. asking
7. Don't_________in class.
A. talking B. to talk C. talked D. talk
8. Students are always interested in____________ a party.
A. to have B. have C. having D. had
9.___________the exams, students have to learn hard.
A. To pass B. Passed C. Pass D. Passing
10. Would you please show me _________ yahoo messenger?
a. to use b. using c. how can I use d. how to use
11. Mary told me _________ to go to the bank
a. don’t forget b. not forget c. not to forget d. should not forget
14. Let him _________ it himself
a. do b. to do c. does d. doing
15. School children are looking forward to _________ on holiday
a. go b. be going c. going d. went
16.
Mr. Minh _________ wearing a crash helmet when he goes somewhere on his motorbike
a. used to b. is used to c. is using d. used
a) \(CuO+2HCl\rightarrow CuCl_2+H_2O\)
b) \(n_{CuO}=\dfrac{4}{80}=0,05\left(mol\right)\)
Theo PTHH: \(n_{CuCl_2}=n_{CuO}=0,05\left(mol\right)\Rightarrow m_{CuCl_2}=0,05.135=6,75\left(g\right)\)
c) mdd sau pư = 156 + 4 = 160 (g)
\(C\%_{CuCl_2}=\dfrac{6,75}{160}.100\%=4,21875\%\)
a, \(A=\dfrac{1}{7}.6+\dfrac{1}{7}.\dfrac{2}{7}+\dfrac{1}{7}.\dfrac{5}{7}=\dfrac{1}{7}\left(6+\dfrac{2}{7}+\dfrac{5}{7}\right)=1\)
b, \(A=\dfrac{4}{3}.\dfrac{13}{9}-\dfrac{4}{3}.\dfrac{40}{9}=\dfrac{4}{3}\left(\dfrac{13}{9}-\dfrac{40}{9}\right)=-4\)
c, \(A=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}.\dfrac{-7}{11}=-\dfrac{5}{11}\)
`A=6/7+[1/7(2/7+5/7)]`
`A=6/7+(1/7*1)`
`A=6/7+1/7`
`A=1`
~~~~~~~~~~~~~~~~~~~
`A=4/3*13/9-4/3*40/9`
`A=4/3(13/9-40/9)`
`A=4/3*(-3)`
`A=-4`
~~~~~~~~~~~~~~~~~~~
`A=5/7(5/11+2/11-14/11)`
`A=5/7(-7/11)`
`A=-5/11`
`A=6/7 + 1/7 . 2/7 + 1/7 . 5/7`
`A = 1/7 . 6 + 1/7 . 2/7 + 1/7 . 5/7`
`A = 1/7 . ( 6 + 2/7 + 5/7)`
`A=1/7 . ( 42/7 + 2/7 + 5/7)`
`A=1/7 . 7`
`A=1`
________________________
`A=4/9 . 13/3 - 4/3 . 40/9`
`A=(4.13)/(9.3) - (4.40)/(3.9)`
`A=(4.13-4.40)/(9.3)`
`A=(4.(13-40))/27`
`A=(4.(-27))/27`
`A=-4`
___________________________
`A = 5/7 . 5/11 + 5/7 . 2/11 - 5/7 . 14/11`
`A =5/7 . ( 5/11 + 2/11 - 14/11)`
`A=5/7 . ((5+2-14)/11)`
`A=5/7 . (-7)/11`
`A=(5xx(-7))/(7xx11)`
`A=(-35)/77`
`A=(-5)/11`
Bạn tham khảo cách làm:
https://hoidap247.com/cau-hoi/179838
\(2x^2-9x+9-2\left(x^2-2x-35\right)=8\)
\(\Leftrightarrow-5x+79=8\Leftrightarrow x=\dfrac{71}{5}\)
`(2x-3)(x-3) - 2(x+5)(x-7)=8`
`2x^2 -9x+9 - 2x^2 -4x - 70 = 8`
`-5x + 79 = 8`
`-5x = -71`
`x=-71 : (-5)`
`x=71/5