Question

solve for x : x+b/a-b=x-b/a+b

Answer 1

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Answer 2

x+b/a-b=x-b/a-b (given)
(a+b)(x+b)=(x-b)(a-b)
ax+ab+bx+b²=ax-bx-ab+b²
transposing all to RHS
ax+ab+bx+b²-ax+bx+ab-b²=0
ax and b² will be canceled 
you will get..
2ab+2bx=0
2b(a+x)=0
transposing 2b to LHS you will get
a+x=0
∴x= -a