Question

Mọi người hướng dẫn và giúp em một số câu làm ví dụ với ạ.Bài 5 ý ạ

Answer 1

1. x²-x-2       

      =(x²-2x)+(x-2)

       = x(x-2)+(x-2) 

       = (x+1)(x-2)

2.x²-3x+2

=x²-x-2x+2

=(x²-x)-(2x-2)

=x(x-1)-2(x-1)

=(x-2)(x-1)

3.-x²-2x+3

=3-2x-x²

=3+x-3x-x²

=(3+x)-(3x+x²)

=(3+x)-x(3+x)

=(1-x)(3+x)

4. x²-5x+4

=x²-x-4x+4

=(x²-x)-(4x-4)

=x(x-1)-4(x-1)

=(x-1)(x-4)

5. x²-5x+6

=x²-2x-3x+6

=(x²-2x)-(3x-6)

=x(x-2)-3(x-2)

=(x-2)(x-3)

6.x²-6x+5

=(x²-x)-(5x-5)

=x(x-1)-5(x-1)

=(x-1)(x-5)

7.x²-7x+12

=(x²-3x)-(4x-12)

=x(x-3)-4(x-3)

=(x-4)(x-3)

8.-x²+7x-12

=(-x²+3x)+(4x-12)

=-x(x-3)+4(x-3)

=(4-x)(x-3)

9.x²-3x-4

=(x²+x)-(4x+4)

=x(x+1)-4(x+1)

=(x-4)(x+1)

mik làm 1 nửa thôi dài quá

Answer 2

bạn đăng nhỏ câu hỏi ra

Answer 3

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

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

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

4) \(x^2-5x+4=\left(x-1\right)\left(x-4\right)\)

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

6) \(x^2-6x+5=\left(x-1\right)\left(x-5\right)\)

Answer 4

7) \(x^2-7x+12=\left(x-3\right)\left(x-4\right)\)

8) \(-x^2+7x-12=-\left(x^2-7x+12\right)=-\left(x-3\right)\left(x-4\right)\)

9) \(x^2-3x-4=\left(x-4\right)\left(x+1\right)\)

10) \(x^2-4x+3=\left(x-1\right)\left(x-3\right)\)

11) \(-x^2+7x+8=-\left(x^2-7x-8\right)=-\left(x-8\right)\left(x+1\right)\)

12) \(-x^2-7x+8=-\left(x^2+7x-8\right)=-\left(x+8\right)\left(x-1\right)\)

Answer 5

13) \(x^2-9x+8=\left(x-1\right)\left(x-8\right)\)

14) \(-x^2-8x+9=-\left(x^2+8x-9\right)=-\left(x+9\right)\left(x-1\right)\)

15) \(x^2-10x+9=\left(x-1\right)\left(x-9\right)\)

16) \(-x^2-9x+10=-\left(x^2+9x-10\right)=-\left(x+10\right)\left(x-1\right)\)

17) \(2x^2-3x-5=\left(2x-5\right)\left(x+1\right)\)

18) \(-2x^2-3x+5=-\left(2x^2+3x-5\right)=-\left(2x+5\right)\left(x-1\right)\)