14.59+(10.72)-25.31=0
设( )=x
14.59+x-25.31=0
x+14.59-25.31=0
0+25.31=x+14.59
x+14.59=25.31
x=25.31-14.59
x=10.72
(49.81)-48.32+78.51=80
设( )=x
x-48.32+78.51=80
x-48.32=80-78.51
x-48.32=1.49
x=1.49+48.32
x=49.81