Đáp án nè:
a. Ta có: b – a= - (a- b) nên ( b – a)2 = [-(a- b)]2 = (-1)2. (a- b)2 = ( a - b)2
[5(a – b)3 +2(a – b)2] : (b – a)2
= [5(a – b)3 +2(a – b)2] : (a - b)2
= 5(a – b)3 : ( a- b)2 + 2(a – b)2 : (a - b)2
= 5(a – b) + 2
b. 5(x – 2y)3 : (5x – 10y) = 5(x – 2y)3 : 5(x – 2y) =(x – 2y)2
c. (x3 + 8y3) : (x + 2y) = [x3 + (2y)3] : (x + 2y)
= (x + 2y)(x2 – 2xy + 4y2) : (x + 2y) = x2 – 2xy + 4y2
HỌC TỐT NHA