(i) 4y – 7z
This expression is binomial because it contains two terms. That is 4 y and -7z.
(ii) y2
This is monomial expression because it contains only one term y2.
(iii) x + y – xy
This is trinomial expression because it contains three terms x, y and -xy.
(iv) 100
This is a monomial expression because it contains only one term 100.
(v) ab – a – b
This is trinomial expression because it contains 3 terms ab, -a and -b.
(vi) 5 – 3t
This is binomial expression because it contains 2 terms 5 and -3t.
(vii) 4p2q – 4pq2
This is binomial expression because it contains two terms 4p2q and – 4 pq2
(viii) 7mn
This is monomial expression because it contains only one term 7mn.
(ix) z2 – 3z + 8
This is trinomial expression because it contains three terms z2, -3z and 8.
(x) a2 + b2
This is binomial expression because it contains two terms a2 and b2.
(xi) z2 + z
This is binomial expression because it contains 2 terms z2 and z.
(xii) 1 + x + x2
This is trinomial expression because it contains 3 terms 1, x and x2.