x2 - 32 = 42
=> x2 - 9 = 16
=> x2 = 16 + 9
=> x2 = 25
=> x2 = 52 = (-5)2
Vậy \(x\in\left\{-5;5\right\}\).
x2 - 32 = 42
=> x2 - 9 = 16
=> x2 = 16 + 9
=> x2 = 25
=> x2 = 52 = (-5)2
Vậy $x\in\left\{-5;5\right\}$x∈{−5;5}.
x2-32=42
=>x2-9=16
=>x2=16+9
=>x2=25
=>x=52=(-5)2
Vậy x\(\in\){-5,5} thỏa mãn