5.12 {x+1>0⇒x>-1 {x-1≠0⇒x≠1 {10-x≥0⇒x≤10 x∈(-1;1) U (1;10] 5.13 {(4-x)(4+x)≥0⇒-4≤x≤4 {x-1≠0⇒x≠1 {lg(x-1)²≠0⇒(x-1)²≠1⇒x-1≠-1 U x-1≠1⇒x≠0 U x≠2 x∈[-4;0) U (0;1) U (1;2) U (2;4] 5,14 {(2-x)(2+x)≥0⇒-2≤x≤2 {-π/2+πnx∈[-2;-π/2) (-π/2;π/2) U (π/2;2]