Question

phân tích đa thức thành nhân tử

a,20x-5y

b,4x²-8xy²+10x²y

c,5x(x-1)-3x(x-1)

d,x(x+y)-6x-6y

e,x⁴-y⁴

f,x²-4y²

g,27x³-64

h,(x+1)²-16

i,(3x+1)²-(x-2)²

Answer 1

a, 20x - 5y = 5(4x - y)
b, 4x² - 8xy² + 10x²y = 2x(2x - 4y² + 5xy)
c, 5x (x - 1) - 3x (x - 1) = (5x - 3x) (x - 1) = 2x (x - 1)
d, x (x + y) - 6x - 6y = x (x + y) - (6x + 6y) = x (x + y) - 6 (x + y) = (x - 6) (x + y)
e, x⁴ - y⁴ = (x²)² - (y²)² = (x² - y²) (x² + y²) = [(x + y) (x - y)] (x² + y²)
f, x² - 4y² = x² - (2y)² = (x - 2y) (x + 2y)
g, 27x³ - 64 = (3x)³ - 4³ = (3x - 4) (9x² + 12x + 16)
h, (x +1)² - 16 = (x +1)² - 4² = (x + 1 + 4) (x + 1 - 4) = (x + 5) (x - 3)
i, (3x + 1)² - (x - 2)² = (3x + 1 - x + 2) (3x + 1 + x - 2) = (2x + 3) ( 4x - 1)