The correct answer is the second one: ±√15/3
Explan ation:
You have the quadratic equation 3x^2−10=−5. Then you must clear the variable "x" as below:
3x^2−10=−5
3x^2=−5+10
3x^2=5
x^2=5/3
x=±√(5/3)
When you multipy the numerator and the denominator by 3 for simplify the result, you obtain:
x=±√(5x3/3x3)
x=±√(15/3²)
When you simplify, you have:
x=±√15/3