Answer:
81 sheep were there on the farm
Explanation:
Consider the provided information.
Let x represents the number of goats.
y represents the number of cows.
z represents the number of sheep.
Therefore, the total number of animals are x+y+z
2/5 of the animals were goats. This can be written as:
![(2)/(5)(x+y+z)=x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/51nb8moz6s4zkda8y9gt3y3hp2rowx23bt.png)
There were three times as many sheep than cows.
![z=3y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/e2mvcvewamgzm2bzqcipqmwugphmg66wrz.png)
There were 45 more goats than cows,
![x=45+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/p2327044pm16qwu5k5xgmltvuo0kvyeeh3.png)
Substitute the value of x and z in equation 1.
![(2)/(5)(45+y+y+3y)=45+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/j983rw705pq9qy1we1u5z3wcjq42umhyxz.png)
![(2)/(5)(45+5y)=45+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/1oqyko1v023z5sv1kstx1c6nwtjkwkrup0.png)
![2(9+y)=45+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2g0m142nn1eyc9yfq9jiltv2dcxrza2szc.png)
![18+2y=45+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5ibaymw3ak6fypahe0a2uoudtjvrn3u7m0.png)
![y=27](https://img.qammunity.org/2020/formulas/mathematics/high-school/upgug9oompjsq7fxr94a8gykvs0go466zu.png)
Hence, there are 27 cows.
Substitute the value of y in
![x=45+y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/p2327044pm16qwu5k5xgmltvuo0kvyeeh3.png)
![x=45+27](https://img.qammunity.org/2020/formulas/mathematics/middle-school/imie03mtwkun83yeim2hm5bkh6nutxk4i1.png)
![x=72](https://img.qammunity.org/2020/formulas/mathematics/middle-school/epmegqmq8t1gonnhjjqe87wzswvjz0a34g.png)
Therefore, there are 72 goats.
Substitute the value of y in
![z=3y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/e2mvcvewamgzm2bzqcipqmwugphmg66wrz.png)
![z=3(27)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/lkfygb0jdh9tfub7trf9kqatggscx1obva.png)
![z=81](https://img.qammunity.org/2020/formulas/mathematics/middle-school/r5ezqhugtwszkbuy0x9kd3pvnnbvf6xfzl.png)
Thus, there are 81 sheep.