The set of integers forms a group under addition because it satisfies the properties of closure, associativity, identity element (0), and inverse elements for each element.

The distributive property states that for any elements a, b, and c in a ring, a * (b + c) = (a * b) + (a * c). This property ensures that multiplication distributes over addition.

The set of complex numbers is a field because it satisfies the properties of a commutative ring and every nonzero element has a multiplicative inverse.

The distributive property states that for any scalar c and vectors u and v in a vector space, c * (u + v) = (c * u) + (c * v). This property ensures that scalar multiplication distributes over vector addition.

The set of all polynomials with real coefficients forms a vector space because it satisfies the properties of closure under vector addition and scalar multiplication, associativity of vector addition, commutativity of vector addition, identity element for vector addition (the zero polynomial), inverse elements for vector addition (additive inverses of polynomials), associativity of scalar multiplication, and distributive property of scalar multiplication over vector addition.

The inverse element property ensures that for every element a in a group, there exists a unique element b in the group such that a * b = b * a = e, where e is the identity element of the group.

The set of integers forms a ring without unity because it satisfies the properties of closure under addition and multiplication, associativity of addition and multiplication, commutativity of addition, identity element for addition (0), and inverse elements for addition (additive inverses of integers), but it does not have a multiplicative identity (unity) because there is no integer that, when multiplied by any other integer, produces that integer.

The multiplicative inverse property ensures that for every nonzero element a in a field, there exists a unique element b in the field such that a * b = b * a = 1, where 1 is the identity element of the field.

The set of all ordered pairs of real numbers forms a vector space over the field of real numbers because it satisfies the properties of closure under vector addition and scalar multiplication, associativity of vector addition, commutativity of vector addition, identity element for vector addition (the zero vector), inverse elements for vector addition (additive inverses of vectors), associativity of scalar multiplication, and distributive property of scalar multiplication over vector addition.

The associative property ensures that for any elements a, b, and c in a group, (a * b) * c = a * (b * c).

The set of complex numbers forms a ring with unity because it satisfies the properties of closure under addition and multiplication, associativity of addition and multiplication, commutativity of addition, identity element for addition (0), inverse elements for addition (additive inverses of complex numbers), identity element for multiplication (1), and inverse elements for multiplication (multiplicative inverses of nonzero complex numbers).

The associative property of scalar multiplication ensures that for any scalar c and vectors u and v in a vector space, c * (u + v) = (c * u) + (c * v).

The set of real numbers is a field, but it is not algebraically closed because there exist polynomials with real coefficients that do not have roots in the set of real numbers. For example, the polynomial x^2 + 1 does not have any real roots.

The identity element property ensures that there exists an element e in a group such that for any element a in the group, e * a = a * e = a.

The set of all ordered pairs of complex numbers forms a vector space over the field of complex numbers because it satisfies the properties of closure under vector addition and scalar multiplication, associativity of vector addition, commutativity of vector addition, identity element for vector addition (the zero vector), inverse elements for vector addition (additive inverses of vectors), associativity of scalar multiplication, and distributive property of scalar multiplication over vector addition.