Question

Answer 1

làm bài mấy vậy bạn

Answer 2

Bài 18:

1: \(\left(x-5\right)\left(x+5\right)=x^2-25\)

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

3: \(\left(x-\dfrac{2}{3}\right)\left(x+\dfrac{2}{3}\right)=x^2-\dfrac{4}{9}\)

4: \(\left(1+2x\right)\left(1-2x\right)=1-4x^2\)

5: \(-\left(2x+3\right)\left(3-2x\right)=4x^2-9\)

6: \(-\left(5x-3\right)\left(3+5x\right)=9-25x^2\)

7: \(-\left(3x-\dfrac{2}{5}\right)\left(3x+\dfrac{2}{5}\right)=\dfrac{4}{25}-9x^2\)

8: \(-\left(2x-\dfrac{2}{3}\right)\left(2x+\dfrac{2}{3}\right)=\dfrac{4}{9}-4x^2\)

Answer 3

Bài 16: 

1: \(x^2+4x+4=\left(x+2\right)^2\)

2: \(x^2+6x+9=\left(x+3\right)^2\)

3: \(4x^2+4x+1=\left(2x+1\right)^2\)

4: \(4x^2+12x+9=\left(2x+3\right)^2\)

5: \(x^2-2x+1=\left(x-1\right)^2\)

6: \(x^2-8x+16=\left(x-4\right)^2\)

7: \(36-12x+x^2=\left(6-x\right)^2\)

8: \(4x^2-12xy+9y^2=\left(2x-3y\right)^2\)​