đề yêu cầu j vậy em?

\(a,x^2-x=x\left(x-1\right)\\ b,5x^2\left(x-2y\right)-15x\left(x-2y\right)=\left(5x^2-15x\right)\left(x-2y\right)=5x\left(x-3\right)\left(x-2y\right)\\ c,3\left(x-y\right)-5x\left(y-x\right)=3\left(x-y\right)+5x\left(x-y\right)=\left(5x+3\right)\left(x-y\right)\)

5x2 (x – 2y)– 15x(x – 2y) = x.5x(x - 2y) - 3.5x(x - 2y)

= (x - 3).5x(x - 2y)

1, \(2x^2+4x=2x\left(x+2\right)\)

2, \(15x^3+5x^2-10x=5x\left(3x^2+x-2\right)=5x\left(x-\dfrac{2}{3}\right)\left(x+1\right)\)

3) \(5x^2\left(x-2y\right)+15x\left(x-2y\right)=\left(5x^2+15x\right)\left(x-2y\right)=5x\left(x+3\right)\left(x-2y\right)\)

4) \(3\left(x-y\right)+5x\left(y-x\right)=\left(x-y\right)\left(3-5x\right)\)

5) \(5x^2-10x=5x\left(x-2\right)\)

6) \(3x-6y=3\left(x-2y\right)\)

7) \(25x^2+5x^3+x^2y=x^2\left(25+5x+y\right)\)

8) \(14x^2y-21xy^2+28x^2y^2=7xy\left(2x-3y+4xy\right)\)

9) \(x\left(y-1\right)-y\left(y-1\right)=\left(x-1\right)\left(y-1\right)\)

10) \(10x\left(x-y\right)-8y\left(y-x\right)=\left(10x+8y\right)\left(x-y\right)=2\left(5x+4y\right)\left(x-y\right)\)

\(1,=2x\left(x+2\right)\\ 2,=5x\left(3x^2+x-2\right)\\ 3,=\left(x-2y\right)\left(5x^2+15x\right)=5x\left(x+3\right)\left(x-2y\right)\\ 4,=\left(x-y\right)\left(3-5x\right)\\ 5,=5x\left(x-2\right)\\ 6,=3\left(x-2y\right)\\ 7,=5x^2\left(5+x+y\right)\\ 8,=7xy\left(2x-3y+4xy\right)\\ 9,=\left(y-1\right)\left(x-y\right)\\ 10,=\left(x-y\right)\left(10x+8y\right)=2\left(5x+4y\right)\left(x-y\right)\)

12.C

13.C

a/ (x-1)²-(4x+3)(2-x)=x²-2x+1-(8x-4x²+6-3x)

=x²-2x+1-8x+4x²-6+3x=5x²-7x-6

b/ (15x³y² - 6x²y³) : 3x²y² = 5x - 2y

c/ \(\dfrac{x+7}{x-7}-\dfrac{x-7}{x+7}+\dfrac{4x^2}{x^2-49}\)=\(\dfrac{\left(x+7\right)^2-\left(x-7\right)^2+4x^2}{\left(x-7\right)\left(x+7\right)}\)=\(\dfrac{x^2+14x+49-\left(x^2-14x+49\right)+4x^2}{\left(x-7\right)\left(x+7\right)}\)=\(\dfrac{28x+4x^2}{\left(x-7\right)\left(x+7\right)}\)=\(\dfrac{4x\left(x+7\right)}{\left(x-7\right)\left(x+7\right)}\)=\(\dfrac{4x}{x-7}\)

Bạn học căn thức chưa ?

phan tich cac da thuc sau thanh nhan tu theo mau:

a)\(2x^3-x\)

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

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

\(=x\left(\sqrt{2}x-1\right)\left(\sqrt{2}x+1\right)\)

b)\(5x^2\left(x-1\right)-15x\left(x-1\right)\)

\(=\left(5x^2-15x\right)\left(x-1\right)\)

\(=5x\left(x-3\right)\left(x-1\right)\)

d)\(3x\left(x-2y\right)+6y\left(2y-x\right)\)

\(=3x\left(x-2y\right)-6y\left(x-2y\right)\)

\(=\left(3x-6y\right)\left(x-2y\right)\)

\(=3\left(x-2y\right)\left(x-2y\right)\)

\(=3\left(x-2y\right)^2\)

A

1) \(=\left(3x^2y-3xy^2\right)+\left(5x-5y\right)=3xy\left(x-y\right)+5\left(x-y\right)=\left(x-y\right)\left(3xy+5\right)\)

2) \(=\left(ax+ay\right)+\left(bx+by\right)=a\left(x+y\right)+b\left(x+y\right)=\left(x+y\right)\left(a+b\right)\)

3) \(=x\left(x-2y\right)-\left(x-2y\right)=\left(x-2y\right)\left(x-1\right)\)

1) \(3x^2y-5y-3xy^2+5x\)

\(=3xy\left(x-y\right)+5\left(x-y\right)\)

\(=\left(3xy+5\right)\left(x-y\right)\)

2) \(ax+by+ay+bx\)

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

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

3) \(x\left(x-2y\right)-x+2y\)

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

\(=\left(x-1\right)\left(x-2y\right)\)