Câu 1 là B nha
Câu 1: A
Câu 2: B
Bài 1: C
Bài 2: A
1,(x+5)^3−x^3−125
=x^3+15x^2+75x+125−x^3−125
=15x(x+5)
(1𝑦/3+3)^3
(𝑦/3+3)^3
(𝑦/3+3⋅3/3)^3
(𝑦+3⋅3/3)^3
(𝑦+9/3)^3