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 = 10 domain = {all real numbers}: range = {y: y = 3} 4. the range and domain of P = (x, y) {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

Answer: {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

Answer: {3, 4, 5, 6}

3. the range and domain of F = 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.

Answer: domain = range = R, the set of real numbers

4. the range and domain of P = y = 3

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

Answer: domain = R, range = {3}