Question

1. Bỏ dấu ngoặc rồi thu gọn biểu thức

a) (x +y) . (x + y)

b) (x- y) . ( x -y)

c) (x + y) . (x -y)

Answer 1

a)(x+y).(x+y)=x(x+y)+y(x+y)=x^2+xy+xy+y^2=x^2+2xy+y^2

b)(x-y).(x-y)=x(x-y)-y(x-y)=x^2-xy-xy+y^2=x^2-2xy+y^2

c)(x+y).(x-y)=x(x-y)+y(x-y)=x^2-2xy+xy-y^2=x^2-y^2

nhớ liek nhé

 

Answer 2

a ,  = \(x^2+2xy+y^2\)

b, = \(x^2-2xy+y^2\)

c = \(x^2-y^2\)