Question

1. Phân tích đa thức thành nhân tử

a. x​3-xy2​+x​​​2-y3

​b. (3x+​1)- (1-2x)³

​c.a³-2a²b+ab²

​d. xy(x+y)+yz(y+​z)+xz(x+z)+​2xyz

​2. Tìm x

​a. x(x-1)+​x-1 = 0

​b. 3(x-3)-4x+12= 0

​c. x³- 5x=0

​d. (3x-2)²- (x+2)²= 0

​e. x²-x-4(x+​3)= 0

​f. 2(x-2)-x²+4x-4=0

​3. Tính nhanh

​a. 47,5.6,3-17,5.3,3-17,5.6,7+3,7.47,5

​b. 43²+40²-17²+80.43

Answer 1

Câu 2: 

a: =>(x-1)(x+1)=0

=>x=1 hoặc x=-1

b: \(\Leftrightarrow\left(x-3\right)=0\)

=>x=3

c: =>x(x^2-5)=0

hay \(x\in\left\{0;\sqrt{5};-\sqrt{5}\right\}\)

d: \(\Leftrightarrow\left(3x-2-x-2\right)\left(3x-2+x+2\right)=0\)

=>(2x-4)(4x)=0

=>x=0 hoặc x=2

e: \(\Leftrightarrow x^2-x-4x-12=0\)

=>x^2-5x-12=0

=>\(x\in\left\{\dfrac{5+\sqrt{73}}{2};\dfrac{5-\sqrt{73}}{2}\right\}\)

f: \(\Leftrightarrow\left(x-2\right)\left(2-x+2\right)=0\)

=>(x-2)(4-x)=0

=>x=2 hoặc x=4