1. the domain set of c = {( 2, 5), (2, 6), (2, 7)} {2} 2. the range set of e = {(3, 3), (4, 4), (5, 5), (6, 6)} domain = range = {all real numbers} 3. the range and domain of f = {(x, y ) | x + y =10} domain = {all real numbers}: range = {y: y = 3} 4. the range and domain of p = {(x, y ) | y = 3} {3, 4, 5, 6}

I think we have to match the answers with the question.

1. the domain set of C = {( 2, 5), (2, 6), (2, 7)}

When we write our relation as sets of ordered pairs (x,y) like this, the domain is the set of x values and the range is the set of y values.   Here the domain is correctly chosen as

{2}

2. the range set of E = {(3, 3), (4, 4), (5, 5), (6, 6)}

The range is the set of y values, so here it's

  {3, 4, 5, 6}

3. the range and domain of F = {(x, y ) | x + y =10}

We can write this as y=10-x.  x can be any real number (that's the domain) and as x ranges over the reals, so does y, so that's the range.

domain = range = R, the set of real numbers

4. the range and domain of P = {(x, y ) | y = 3}

x again can be anything but y is only ever 3.

domain = R, range = {3}

let m = monomial

let t = trinomial

so, m times t = t.

monomial times a trinomial = another trinomial.