Question

determinati numerele naturale xsi y stiind ca: a) {1,2,x} U, {1,2}={1,2,4} b) {2,4,x}U{x,3}={1,2,3,4}​
va rog mult !!!
urgent va rog dau coroana!

Answer 1

$a)\quad \{1,2,x\} \cup \{1,2\} = \{1,2,4\} \Leftrightarrow \{1,2,x\} = \{1,2,4\} \\ \Rightarrow x = 4 \\ \\ b)\quad \{2,4,x\} \cup \{x,3\} = \{1,2,3,4\} \Leftrightarrow \{2,3,4,x\} = \{1,2,3,4\} \\ \Rightarrow x = 1$