\(PT< =>5x\left(x-2\right)-10\left(x-2\right)=0\)

\(< =>\left(x-2\right)\left(5x-10\right)=0\)

\(< =>\left[{}\begin{matrix}x-2=0\\5x-10=0\end{matrix}\right.\)

\(< =>x=2\)

\(PT< =>x\left(x^2-16\right)=0\)

\(< =>\left[{}\begin{matrix}x=0\\x^2-16=0\end{matrix}\right.< =>\left[{}\begin{matrix}x=0\\x=\pm4\end{matrix}\right.\)

\(\%^{35}Cl=100\%-24,23\%=75,77\%\)

\(\overline{Cl}=\dfrac{37.24,23+35.75,77}{100}=35,4846\)

\(\%m_{^{37}Cl}=\dfrac{37.0,7577}{1+35,4846+16.4}.100\%\approx26,392\%\)

Theo đề bài ta có:

\(\left\{{}\begin{matrix}p+n+e=60\\p=n\end{matrix}\right.< =>\left\{{}\begin{matrix}3p=60\\p=n\end{matrix}\right.\)

==> \(\left\{{}\begin{matrix}p=e=\dfrac{60}{3}=20\left(hạt\right)\\p=n=20\left(hạt\right)\end{matrix}\right.\)

Số đơn vị điện tích hạt nhân: \(Z=n_P=20\)

36C

37F

38A

39D

40E

Câu thừa là câu B nhé

1.goes

2.raining

3.don't / walk

4.swam

5.is running

1.Yesterday a little child got lost and then a policeman helped him to find out the way home.

2.This charity organization is popular nationwide.

3.They have a co-educational program for young girls and boys.

4.The Y & Y helps to encourage young children to participate in a recycling program.

5.We should save our natural resources by reusing and recycling the used things.

6.She is organizing for the activities for her summer vacation.

7.Please fill in the application form with your personal information.

8.We should help the handicapped children with their homework.

9.BSA is a youth organization.

10.We should take care of our citizenship and personal fitness.

Thắc mắc câu nào thì hỏi mình nhé

Ex1: D

Ex2:

1.True

2.True

3.False

4.False

5.True

6. Not given

7. False

8.True

D

B

C

A

D

BÀi A:

1.F

2.T

Bài B:

3.She is 74

4.Yes, she is

5.Her father is tall and big,he is taller than her mother