643-(581-b)=292
643-581+b=292
62+b=292
b=292-62
b=230
981-(x+694)=519
981-x-694=519
287-x=519
-x=519-287
-x=232
x=-232
3,128-(m+425)=1,509
3,128-m-425=1,509
-421,872-m=1,509
-m=1,509+421,872
-m=421,381
m=421,381
643-(581-b)=292
643-581+b=292
62+b=292
b=292-62
b=230
981-(x+694)=519
981-x-694=519
287-x=519
-x=519-287
-x=232
x=-232
3,128-(m+425)=1,509
3,128-m-425=1,509
-421,872-m=1,509
-m=1,509+421,872
-m=421,381
m=421,381