The first chapter exercise 1. 1- 1 belongs to 2, 3, 4, 5, 6, 2. 1, 2, 3. 1, {2, 3, 4, 5. -2} 3, b = {0, 1, 2} 4. 1, {y ︱ y = x squared -4, x belongs to r} = {y ︱ y ≥-4} 2, {x belongs to r ︱. Proper subset. a = { x︱2≤x < 4 } b = { x︱3x—7≥8—2x } = { x︱x≥3}∴a∪b = { x︱2≤x . 8 } b = { 1，2，3} C = {3，4，5，6} ∴ A ∩ B = { 1，2，3 }，A ∩ C = {3，4，5，6}。 I'll send you another copy tomorrow.