Question

Bài 1 : Khai triển lũy thừa

a) ( 3x - 5 )²

b) ( 2x + y )²

c) ( 2x - 3y )²

d) ( 2x - 3y )³

Answer 1

\(a,=9x^2-2.3x.5+25=9x^2-30x+25\\ b,=4x^2+2.2x.y+y^2\\ =4x^2+4xy+y^2\\ c,=4x^2-2.2x.3y+9y^2\\ =4x^2-12xy+9y^2\\ d,=8x^3-3.4x^2.3y+3.2x.9y^2-27y^3\\ =8x^2-36x^2y+54xy^2-27y^3\)