Question

3.(x + 3) - x² + 9

Answer 1

3(x+3)-x²+9
= 3(x+3) - (x² - 9) = 3(x + 3) - (x + 3)(x - 3)
= (x + 3)(3 - x + 3) = (6 - x)(x+3)

Answer 2

3.(x + 3) - x² + 9

= (x + 3) - (x² - 9)

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

= (x + 3)(1 - x + 3)

= (x + 3)(4 - x)

#Học tốt!