Question

C={x apartine N| x -3 =8 sau 2× x + 2 = 18 sau x + 1 mai mic sau egal 6]

Answer 1

x-3=8
x=8+3
x=11
sau
2x+2=18
2x=18-2
2x=16
x=16:2
x=8
sau
x+1≤6
x≤6-1
x≤5⇒ x∈{0,1,2,3,4,5}
C={11} U {8} U {0,1,2,3,4,5}
C= {0,1,2,3,4,5,8,11}