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\(4x^2-25+\left(2x+7\right).\left(5-2x\right)\)

\(=\left(2x+5\right).\left(2x-5\right)-\left(2x+7\right).\left(2x-5\right)\)

\(=\left(2x+5-2x-7\right).\left(2x-5\right)\)

\(=-2.\left(2x-5\right)\)

\(a^2x^2-a^2x^2-b^2x^2+b^2y^2\)

\(=a^2.\left(x^2-y^2\right)-b^2.\left(x^2-y^2\right)\)

\(=\left(a^2-b^2\right).\left(x^2-y^2\right)\)

\(=\left(a-b\right).\left(a+b\right).\left(x-y\right).\left(x+y\right)\)

\(x^2-y^2+12y-36\)

\(=x^2-\left(y^2-12y+36\right)\)

\(=x^2-\left(y-6\right)^2\)

\(=\left(x-y+6\right).\left(x+y-6\right)\)

\(\left(x+2\right)^2-x^2+2x-1\)

\(=\left(x+2\right)^2-\left(x^2-2x+1\right)\)

\(=\left(x+2\right)^2-\left(x-1\right)^2\)

\(=[x+2-\left(x-1\right)].[x+2+\left(x-1\right)]\)

\(=\left(x+2-x+1\right).\left(x+2+x-1\right)\)

\(=3.\left(2x+1\right)\)

\(16x^2-y^2=\left(4x\right)^2-y^2=\left(4x-y\right).\left(4x+y\right)\)

\(1+27x^3=1^3+\left(3x\right)^3=\left(1+3x\right).\left(1-3x+9x^2\right)\)

sao bạn hỏi dài thế, mỗi lúc một câu thui

chỗ AB < AC kia các bn chuyển thành chữ " và " nhé. Mk viết nhầm

Program tinhtoan;

Var a,b,c,d : integer;

Begin

Write(‘Nhap hai so a,b :’);

Readln (a,b);

c:=a div b;

d:=a mod b;

Writeln(‘ Phan nguyen cua a va b la :’,c);

Writeln(‘ Phan du cua a va b la :’,d);

Readln;

End.

7. D

8. B

9. B

10. D

11. B

12.

13. D

14. D

15. A. 

đúng thì tk hộ

TL

 d, so as to protect

HT

Đáp án B

Nhớ k cho mik nha