Răspuns:
A= { 2x+3≤9}= {... -5.-4. -3.-2.-1, 0,1,2,3]
B= { 3x+7≥1}= {-2, -1, 0, 1,2, 3,4...}
2x+3≤9 2x≤6 x≤6:2 x≤3 x∈(-∞, 3]
3x+7≥1 3x≥-6 x≥-6:3 x≥-2 x∈[-2,∞)
A∩B= [-2, 3]
AxB= {(-5,-2); (-5, -1); (-5, 0); (-5,1); (-5,2); (-5,3); ...(3,-2);(3,-1); (3,0);(3,1);(3,2);(3,3)}
BxA={(-2,-5); (-2,-4)...(2,-5);(2,-4)...(4,-5);(4,3)}