There were 35 birds and 17 cats
B+C = 52
2B + 4C = 138
B+C-C = 52-C
B= 52-C
Take this formula and substitute in 2B + 4C = 138.
2 (52-C) + 4 C =138
Distribute
104 -2C + 4C = 138
Combine like tems
104 + 2C = 138
104 - 104 + 2C =138 - 104
2C = 34
2C/2 = 34/ 2
C = 17
B + C =52
B + 17 =52
B +17 -17 = 52- 17
B = 35
to grant women the right to vote
