Question 1046797
1)  From 3x^2=2a, we divide by 3 and get
x^2 = (2/3)a
then take the square root and get
x = {{{+-sqrt(2a/3)}}}
which can be simplified by rationalizing...
2)  For x^2 - 3x - 15 = 0, we will have to use the quadratic formula, since it isn't factorable...we get
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{x = (3 +- sqrt(9 - 4*1*(-15)))/2 }}}
{{{x = (3 +- sqrt(69))/2}}}