The sum of -7.7 and -7.7 is -15.4. That is: -7.7 + (-7.7) = -15.4. This is exactly the same as saying -7.7 - 7.7 = -15.4.
The sum of -80 and 77 is -3
-15.4
12 + 77 = 89
38 + 39 = 77
99
The numbers 40.5 and 36.5 have a difference of 4 and a sum of 77.
The sum of 7 plus 71 is 77.
672.72 repeating
If: 2+3x = 77 Then: x = 25
77
The sum of the first 8 prime numbers is 77.
The sum is basically 38 x 77 which is 2926