Need with problem which of the following disjunctions is false? 4 · 3 = 11 or 4 + 5 = 10 7 -2 = 5 or 2 · 4 = 7 1 + 8 = 12 or 5 · 3 = 15 7 · 2 = 14 or 4 + 5 = 9

A disjunction is false if and only if both statements are false.
Otherwise it is true

4 · 3 = 11 or 4 + 5 = 10 → F ∨ F
7 -2 = 5 or 2 · 4 = 7 → T ∨ F
1 + 8 = 12 or 5 · 3 = 15 → F ∨ T
7 · 2 = 14 or 4 + 5 = 9 → T ∨ T
Therefore your answer is 4 · 3 = 11 or 4 + 5 = 10