78 + x = 122 + 68
x = 68 + 122 – 78
x = 112
a – 750 = 1000 – 920
a = – 920 + 1000 + 750
a = 830
955 – b = 120 + 325
– b = 325 + 120 – 955
-b = -510
b = 510
78 + x = 122 + 68
x = 68 + 122 – 78
x = 112
a – 750 = 1000 – 920
a = – 920 + 1000 + 750
a = 830
955 – b = 120 + 325
– b = 325 + 120 – 955
-b = -510
b = 510