Câu hỏi của Núi non tình yêu thuần k...

Question

Phân tích các đa thức sau thành nhân tử:

$b,x^2+6x+5$

$c,x^2-7x+10$

Quoc Tran Anh Le · Accepted Answer

b, $x^2+6x+5$

$=x^2+6x+9-4$

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

$=\left(x+3-2\right)\left(x+3+2\right)$

$=\left(x+1\right)\left(x+5\right)$

c, $x^2-7x+10$

$=x^2-7x+12,25-2,25$

$=\left(x-\dfrac{7}{2}\right)^2-\left(\dfrac{3}{2}\right)^2$

$=\left(x-\dfrac{7}{2}-\dfrac{3}{2}\right)\left(x-\dfrac{7}{2}+\dfrac{3}{2}\right)$

$=\left(x-5\right)\left(x-2\right)$Câu trả lời: b, $x^2+6x+5$

$=x^2+6x+9-4$

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

$=\left(x+3-2\right)\left(x+3+2\right)$

$=\left(x+1\right)\left(x+5\right)$

c, $x^2-7x+10$

$=x^2-7x+12,25-2,25$

$=\left(x-\dfrac{7}{2}\right)^2-\left(\dfrac{3}{2}\right)^2$

$=\left(x-\dfrac{7}{2}-\dfrac{3}{2}\right)\left(x-\dfrac{7}{2}+\dfrac{3}{2}\right)$

$=\left(x-5\right)\left(x-2\right)$

Chúc Nguyễn · Answer

b) x2 + 6x + 5

= x2 + x + 5x + 5

= x.(x + 1) + 5.(x + 1)

= (x + 1).(x + 5)

c) x2 - 7x + 10

= x2 - 2x - 5x + 10

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

= (x - 2).(x - 5)Câu trả lời: b) x2 + 6x + 5