规律题目``咋做`?①(x-y)(x+y)=_____②(x-y)(x+y)(x^2+y^2)=________④(x-
1个回答

①(x-y)(x+y)=x^2-y^2

②(x-y)(x+y)(x^2+y^2)=x^4-y^4

④(x-y)(x+y))(x^2+y^2))(x^4+y^4)=x^8-y^8

第五个式子是(x-y)(x+y))(x^2+y^2))(x^4+y^4)(x^8+y^8)(x^16+y^16)=(x^32-y^32)

8(3^2+1)(3^4+1)…(3^32+1)

=[8(3^2-1)(3^2+1)(3^4+1)…(3^32+1)]/(3^2-1)

=8(3^64-1)/(3^2-1)

=3^64-1