Question

daca |x+3|+|y-3|=0 atunci x•y=?

Answer 1

$|x+3| + |y-3| = 0\Rightarrow \Big\{x+3 = 0 \quad si \quad y-3 = 0 \Big\} \\ \tex{ } \geq0 \quad \quad \geq 0 \\ \\ \Rightarrow \Big\{x = -3 \quad si \quad y = 3\big\} \Rightarrow x\cdot y = -3\cdot 3 \Rightarrow \boxed{x\cdot y = -9}$