uses crt;

var a:array[52..101]of integer;

i,n,t:integer;

begin

clrscr;

repeat

write('Nhap n='); readln(n);

until (51<n) and (n<102);

for i:=52 to n do 

 begin

write('A[',i,']='); readln(a[i]);

end;

t:=0;

for i:=52 to n do 

  if i mod 2=0 then t:=t+a[i];

writeln(t);

readln;

end.

2 have been reading - haven't finished

3 have gone

4 am going to have

5 have washed

6 have broken

7 add - mix

8 have used

9 have lived

10 is always doing

11 am going

12 has taught

13 have already bought

14 always meet

4 đáp án là A,B,C,D nhé

1 B

2 D

3 D

4 B

5 A

6 C

7 D

8 A

9 C

1 She advised him to go on holiday when the weather got warmer

2 She warned them to keep out of that room at all time

3 He reminded me to post those letter

4 He asked them not to go into his study

5 I told him not to wait for me

7 She advised him not to go on holiday yet

8 She warned them against entering that room

1 D

2 A

3 C

4 A

5 B

6 C

7 C

8 C

9 A

10 A

^A =130 

^B =130 

mà 2 góc này ở vị trí sole trong 

⇒a//y(1)

^O=180⇒^O1=180-130

⇒^O1=50 

Mà Ox là  tia phân giác ⇒ ^O1=^O2=50

⇒^O2=B=50

Mà 2 góc này ở vị tri sole trong 

⇒y//b(2)

Từ (1)(2)⇒a//b

A nhá

\(P=x^4+2x^2+1+x^4+2x^3+x^2-3\)

\(P=2x^4+2x^3+3x^2-2\)

\(P=x^2\left(2x^2+2x+3\right)-2=\dfrac{1}{2}x^2\left[\left(2x+1\right)^2+5\right]-2\ge-2\)

\(P_{min}=-2\) khi \(x=0\)