Phân tích các đa thức sau thành nhân tử

Question

Answer 1

a)  =  = (a + b)[9(a + b) - 1] = (a + b)(9a + 9b - 1)

b) (mx + my) + (3x + 3y) = mx + my + 3x + 3y = x(m + 3) + y (m + 3) = (x + y)(m + 3)

c) 12xy - 6x - 2y + 1 = 6x(2y - 1) - (2y - 1) = (6x - 1)(2y - 1)

d)  =  = 7y(xy - 1) - 5x(xy - 1) = (7y - 5x)(xy - 1)

e) 2x(x - y) - 4x + 4y = 2x(x - y) - 4(x - y) = (2x - 4)(x - y)

f)  =  = 3(5xy + 1) + 4x(5xy + 1) = (3 + 4x)(5xy + 1)

g)  =  =  = 

h)  =  = 

i)  =  =  = 

j) (2a - b)(b - c) - (b - 2a)(b + c) = (2a - b)(b - c) - [-(2a - b)](b + c) = (2a - b)(b - c) + (2a - b)(b + c) = (2a - b)[(b - c) + (b + c)] = (2a - b)(b - c + b + c) = (2a - b).2a

k) (7x - 3y)(a + b) + (3y - 7x)(a - b) = (7x - 3y)(a + b) + [-(7x - 3y)](a - b) = (7x - 3y)(a - b) - (7x - 3y)(a + b) = (7x - 3y)[(a - b) - (a + b)] = (7x - 3y)(a - b + a + b) = (7x - 3y).2b