Question

PHÂN TÍCH ĐA THỨC THÀNH NHÂN TỬ

c) \(x^2-8x-9\) 

d) \(x^2+14x+48\)

Answer 1

c) x² - 8x - 9

= x² + x - 9x - 9

= x.(x+1) - 9.(x+1)

= (x+1).(x-9)

d) x² + 14x + 48

= x² + 8x + 6x + 48

= x.(x+8) + 6.(x+8)

= (x+8).(x+6)

Answer 2

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

d/ \(x^2+14x+48=x^2+6x+8x+48=x\left(x+6\right)+8\left(x+6\right)=\left(x+6\right)\left(x+8\right)\)

Answer 3

c) \(x^2-8x-9\)

\(=x^2+x-9x-9\)

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

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

d) \(x^2+14x+48\)

\(=x^2+6x+8x+48\)

\(=x\left(x+6\right)+8\left(x+6\right)\)

\(=\left(x+6\right)\left(x+8\right)\)