Answer:
x=√2 or x=−√2
Let's solve your equation step-by-step. 
6=3x2 
Step 1: Subtract 3x^2 from both sides. 
6−3x2=3x2−3x2 
−3x2+6=0 
Step 2: Subtract 6 from both sides. 
−3x2+6−6=0−6 
−3x2=−6 
Step 3: Divide both sides by -3. 
−3x2 
−3 
= 
−6 
−3 
x2=2 
Step 4: Take square root. 
x=±√2 
x=√2 or x=−√2