Question

phân tích thành nhân tử

a) mx + my + 5x + 5y

b) ma + mb - a - b

c) 1 - xa - x + a

d) (a - b)^2 - ( b-a)(a+b)

Answer 1

a) mx + my + 5x + 5y

= m(x+y) +5(x+y)

= (m+5)(x+y)

b) ma + mb - a - b

= m(a+b) - (a+b)

= (m-1)(a+b)

c) 1 - xa - x + a

= - (xa +x) + (1+a)

= - x(a+1) + (1+a)

= (-x+1)(1+a) = (1-x)(1+a)

c) (a-b)^2 - (b-a)(a+b)

= (b-a)^2 - (b-a)(a+b) = (b-a)(b-a) - (b-a)(a+b)

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

= (b-a)(b-a-a-b)

= (b-a).(-2a) = -2a(b-a) = 2a(a-b)

Answer 2

a) mx+my+5x+5y

= m(x+y)+5(x+y)

=(x+y)(m+5)

b) ma+mb-a-b

=m(a+b)-(a+b)

= (a+b)(m-1)

c) 1-xa-x+a

= (1-x)-(xa-a)

= (1-x)-a(x-1)

=(1-x)+a(1-x)

= (1-x)(1+a)

d) (a-b)²-(b-a)(a+b)

= (a-b)²+(a-b)(a+b)

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

= (a-b)(a²-b²)

=(a-b)(a-b)(a+b) = (a-b)²(a+b)