Method 1 (without using an equation):
Total number of goats and sheep is 9. Since her brother counts 4 goats, the remaining animals must be sheep.
Calculating 9 minus 4 gives 5 sheep.
Method 2 (using an equation):
Let x equal the number of sheep present. Since there are 4 goats, total animals are x + 4, which equals 9.
Set up the equation: x + 4 = 9
Subtract 4 from both sides to find x:
x = 9 - 4
x = 5
Alternate Method 3 (using an equation):
Assuming the total animals are 9, then the amount of goats is 9 - x (where x is sheep).
Since her brother counts 4 goats,
9 - x = 4
which rearranges to
x = 9 - 4
x = 5
Therefore, there are 5 sheep.