3.
a=1234
b=1233
c=1234+2731
c=3965
a+b+c=1234+1233+3965=6432
4.
x-17043=122846
x=122846+17043
x=139889
y-(317203+1714)=61050
y-318917=61050
y=61050+318917
y=379967
z-112062-4303=71634
z-116365=71634
z=71634+116365
z=187999
t-42908=101020+53061
t-42908=154081
t=154081+42908
t=196989