Question 1074239
<pre><b>
Suppose the equation is

{{{abs(x+A)=B}}}

where B is non-negative.

Then we solve it as we would if we knew
the values of A and B:

x+A = B;   x+A = -B  

x = B-A;   x = -B-A

So the solutions are B-A and -B-A

If we choose B-A to be the 21 and -B-A to be the 9,
we have this system of equations

{{{system(B-A=21,-B-A=9)}}}

Solve that and get B = 6 and A = -15

So the equation

{{{abs(x+A)=B}}}

becomes:

{{{abs(x-15)=9}}}

Edwin</pre><b>