We define the variables first:
x = number of male cousins
y = number of females cousins
We write the system of equations:
x + y = 9
x = y-2
We solve the system:
Equation 1:
x + y = 9
(y-2) + y = 9
2y-2 = 9
y = 11/2 = 5.5
Equation 2:
x = 5.5-2
x = 3.5
Answer:
Although physically it does not make sense, mathematically the answer is:
number of male cousins = 3.5
number of females cousins = 5.5