Question

Thực hiện phép tính (các bạn ơi giúp mình nhé :((( mai mình thi rồi)

1/ 4x² . (5x³ + 2x - 1)

2/ 4x³y² : x²

3/ (15x²y³ - 10x³y³ + 6xy) : 5xy

4/ (5x³ + 14x² + 12x + 8) : (x + 2)

5/ 7/2x + 11/3y²

6/ x/x+2 + 3/(x+2)(4x-7)

7/ 3/x-y - 2x²/x+y

8/ (1/2) x²y² . (2x+y) (2x-y)

9/ (x-1/2) (x+1/2) (4x-1)

10/ 3x/2x+6 + 6-x/2x²+6x

11/ x²-1/2x-2 + 3x+3/1-x²

12/ x²/x²-y² - xy/x²-y²

13/ 2/2x-3 + x/x-1 - 5x+3/2x²+3-5x

15/ (x-y) (x²+xy+y²) + 2y³ : y³

Answer 1

1: \(=20x^5+8x^3-4x^2\)

2: \(=4xy^2\)

3: \(=3xy^2-2x^2y^2+\dfrac{6}{5}\)

4: \(=\dfrac{5x^3+10x^2+4x^2+8x+4x+8}{x+2}=5x^2+4x+4\)

5: \(=\dfrac{7}{2x}+\dfrac{11}{3y^2}=\dfrac{21y^2+22x}{6xy^2}\)

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

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

8: \(=\dfrac{1}{2}x^2y^2\left(4x^2-y^2\right)=2x^4y^2-\dfrac{1}{2}x^2y^4\)

9: \(=\left(x-\dfrac{1}{4}\right)\left(4x-1\right)=4\left(x-\dfrac{1}{4}\right)^2=4\left(x^2-\dfrac{1}{2}x+\dfrac{1}{16}\right)\)

\(=4x^2-2x+\dfrac{1}{4}\)

10: \(=\dfrac{3x^2+6-x}{x\left(2x+6\right)}=\dfrac{2x+6}{x\left(2x+6\right)}=\dfrac{1}{x}\)

11: \(=\dfrac{x+1}{2}-\dfrac{3}{x-1}\)

\(=\dfrac{x^2-7}{2\left(x-1\right)}\)

12: \(=\dfrac{x^2-xy}{\left(x-y\right)\left(x+y\right)}=\dfrac{x}{x+y}\)

15:=x^3-y^3+2