Question

7. Aflaţi cardinalul mulţimii:

Answer 1

Explicație pas cu pas:

A = {3, 4, 5, 6, 7, 8, 9, 10}

=> card(A) = 8

x - 3 < 8 <=> x < 8 + 3 => x < 11

B = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

=> card(B) = 11

x² < 100 <=> x² < 10² => x < 10

C = {1, 2, 3, 4, 5, 6, 7, 8, 9}

=> card(C) = 9