Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(x^2+6x+5=x\left(x+1\right)+5\left(x+1\right)=\left(x+1\right)\left(x+5\right)\)
(x2 + 6x + 5)(x2 - 10x + 21) - 20
= (x2 + x + 5x + 5)(x2 - 3x - 7x + 21) - 20
= (x + 1)(x + 5)(x - 3)(x - 7) - 20
= (x2 -2x - 3)(x2 - 2x- 35) - 20
Đặt x2 - 2x - 19 = a
=> (a + 16)(a - 16) - 20 = a2 - 256 - 20 = a2 - 276
= \(\left(a-2\sqrt{69}\right)\left(a+2\sqrt{69}\right)\)
= \(\left(a^2-2x-19-2\sqrt{69}\right)\left(x^2-2x-19+2\sqrt{69}\right)\)
C1:
x2-6x+5=x2-x-5x+5=(x2-x)-(5x-5)=x(x-1)-5(x-1)=(x-5)(x-1)
C2:
x2-6x+5= (x2-6x+9)-4=(x-2)2-22=(x-2-2)(x-2+2)=x(x-4)
\(x^2-x-12=x^2-x+\frac{1}{4}-\frac{1}{4}-12=\left(x-\frac{1}{2}\right)^2-\frac{49}{4}=\left(x+3\right)\left(x-4\right)\)
\(x^2-x-12=x^2-4x+3x-12=x\left(x-4\right)+3\left(x-4\right)=\left(x-4\right)\left(x+3\right)\)
Bài 1 :
\(x^2-6x+8=x^2-2x-4x+8=x\left(x-2\right)-4\left(x-2\right)=\left(x-4\right)\left(x-2\right)\)
Bài 2 :
\(x^8+x^7+1=x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1-x^6-x^5-x^4-x^3-x^2-x\)
\(=x^6\left(x^2+x+1\right)+x^3\left(x^2+x+1\right)+x^2+x+1-x^4\left(x^2+x+1\right)-x\left(x^2+x+1\right)\)
=\(\left(x^2+x+1\right)\left(x^6+x^3+1-x^4-x\right)\)
Tick đúng nha
(1+x2)2−4x(1−x2)
= \(-\left(1-x^2\right)^2-4x\left(1-x^2\right)\)
đặt \(\left(1-x^2\right)\)= a
ta có :
- a . a - 4x .a
= a ( - a - 4x )
thay a = \(\left(1+x^2\right)\) ta có
\(\left(1+x^2\right)\left(1-x^2-4x\right)\)
phân tích tiếp nhé !
x2-6x+5
=x2-5x-x+5
=x(x-5)-(x-5)
=(x-5)(x-1)
\(x^2-6x+5\)
\(=x^2-x-5x+5\)
\(=x\left(x-1\right)-5\left(x-1\right)\)
\(=\left(x-1\right)\left(x-5\right)\)