Question

phân tích các đa thức sau thành nhân tử:

a, a(x-y)+bx-by

b, ac+bc+a+b

c, 5a\(^2\) -5ax-7a+7x

d, 7z\(^2\)-7yz-4z+4y

e, x\(^3\)+3x\(^2\)+3x+9

f, x\(^3\) -x\(^2\)y -x\(^2\)z-xyz

g, pq -p\(^2\)-5(p-q)

Answer 1

a,  a(x-y) + bx - by = a(x - y ) +b.(x-y) = (x-y)(a-b)

b, ac+bc + a + b = c.(a+b) +(a+b) = (a+b)(c+1)

c, \(5a^2-5ax-7a+7x=5a.\left(a-x\right)-7.\left(a-x\right)=\left(a-x\right)\left(5a-7\right)\)

d, \(7z^2-7yz-4z+4y=7z.\left(z-y\right)-4.\left(z-y\right)=\left(z-y\right)\left(7z-4\right)\)

e, \(x^3+3x^2+3x+9=x^2.\left(x+3\right)+3\left(x+3\right)=\left(x+3\right)\left(x^2+3\right)\)

g, \(pq-p^2-5\left(p-q\right)=p.\left(q-p\right)+5\left(q-p\right)=\left(q-p\right)\left(p+5\right)\)