Question

phân tích thành nhân tử

a) (x-4)^2 - (x+3)(x-4)

b) 16- a^2 - 2ab - b^2

c)4x^2 -17x + 13

Answer 1

a) (x-4)²-(x+3)(x-4)

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

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

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

= -7(x-4)

b) 16-a²-2ab-b²

= 16-(a²+2ab+b²)

= 4²-(a+b)²

= [4-(a+b)][4+(a+b)]

= (4-a-b)(4+a+b)

c) 4x²-17x+13

= 4x²-4x-13x+13

= (4x²-4x)-(13x-13)

= 4x(x-1)-13(x-1)

= (x-1)(4x-13)

Answer 2

a) (x - 4)² - (x + 3)(x - 4)= (x - 4)(x - 4 - (x + 3))

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

= - 7(x - 4)

b) 16 - a² - 2ab - b²

= 16 - (a² + 2ab + b²)

= 4² - (a + b)²

= (4 - (a + b))(4 + (a + b))

= (4 - a - b)(4 + a + b)

c) 4x² - 17x + 13

= 4x² - 4x - 13x + 13

= 4x(x - 1) - 13(x - 1)

= (x - 1)(4x - 13)

pn coi kt lại nhé