Determinati A ∪ B,A ∩ B ,A-B si B-A, PENTRU MULTIMILE . a)A={a,b.c}.B={b.c.d}, b)A={1,2,3.4},B={x1,2,5,6} c)A={2,4,6,8,10},B={1,3,5,7} d)A={x∈N5x-1≤24},B={x∈N/3x+1<15} e)A={x∈N/7≤x+5<15}.B={x∈N/3<2x+1<15} f)A={x∈N/xpatrat perfect,x<70},B={x∈N/x cub perfect,x<70} ajutatima va ro urgent multumesc
economist a) A U B = { a,b,c,d}, A intersectat B = { b,c}, A-B ={a}, B - A = { d} b) A U B ={1,2,3,4,5,6}, A inters. B ={ 2}, A - B ={3,4}, B - A ={5,6} c) A U B={1,2,3,4,5,6,7,8,10}, A inters. B ={Ф}, multimea vida, A - B ={2,4,6,8,10}, B - A ={1,3,5,7} d) se rezolva inecuatiile pt multimea A si B pt. multimea A, Inecuatia 5x - 1 ≤ 24 ⇔ 5x ≤ 24 + 1 ⇔ 5x ≤ 25 ⇔ x ≤ 25/5 ⇔ x ≤ 5, x ∈ ( - 00, 5], deci x ∈ N si x ∈( - 00, 5} ⇒ x ∈{ 0,1,2,3,4,5}, deci multimea A este A = { 0,1,2,3,4,5} pt. multimea B, inecuatia 3x + 1< 15⇔3x < 15 - 1⇔ 3x < 14⇒ x< 14/3⇒ x ∈ ( - 00, 14/3) si x ∈ N ⇒ x ∈ { 0,1,2,3,4}, doar nr/ naturale 14:3 =4,6⇒ deci se iau nr. pana la 4 B={0,1,2,3,4,5} si A =0,1,2,3,4,5,}⇒ A = B ={0,1,2,3,4,5} A U B= {0,1,2,3,4,5}, A inters. B = {Ф}, A- B ={Ф}, B - A ={Ф"
b) A U B ={1,2,3,4,5,6}, A inters. B ={ 2}, A - B ={3,4}, B - A ={5,6}
c) A U B={1,2,3,4,5,6,7,8,10}, A inters. B ={Ф}, multimea vida, A - B ={2,4,6,8,10}, B - A ={1,3,5,7}
d) se rezolva inecuatiile pt multimea A si B
pt. multimea A, Inecuatia 5x - 1 ≤ 24 ⇔ 5x ≤ 24 + 1 ⇔ 5x ≤ 25 ⇔
x ≤ 25/5 ⇔ x ≤ 5, x ∈ ( - 00, 5], deci
x ∈ N si x ∈( - 00, 5} ⇒ x ∈{ 0,1,2,3,4,5}, deci multimea A este
A = { 0,1,2,3,4,5}
pt. multimea B, inecuatia 3x + 1< 15⇔3x < 15 - 1⇔ 3x < 14⇒ x< 14/3⇒
x ∈ ( - 00, 14/3) si x ∈ N ⇒ x ∈ { 0,1,2,3,4}, doar nr/ naturale 14:3 =4,6⇒ deci se iau nr. pana la 4
B={0,1,2,3,4,5} si A =0,1,2,3,4,5,}⇒ A = B ={0,1,2,3,4,5}
A U B= {0,1,2,3,4,5}, A inters. B = {Ф}, A- B ={Ф}, B - A ={Ф"