Question 830574
{{{b/(x-a) = (2b)/(x+a)}}} solve for x 
Cross multiply
b(x+a) = 2b(x-a)
distribute
bx + ab = 2bx - 2ab
bx - 2bx = -2ab-ab
combine terms
-bx = -3ab
multiply by =-1
bx = 3ab
x = {{{(3ab)/b}}}
cancel b
x = 3a