A:若2x+3=y﹣7,则2x+5=y﹣9
B:若0.25x=﹣4,则x=﹣1
C:若m﹣2=n+3,则m﹣n=2+3
D:若﹣ 13 y=﹣1,则y=﹣3
What ____ you do ____ ____?