Answer:
We can't find a unique price for an apple and an orange.
Explanation:
Suppose, the price of an apple is
and the price of an orange is
![y](https://img.qammunity.org/2020/formulas/mathematics/college/uw0b7dbqmfpakodpw1nh8u5h9nrcutx8vw.png)
They need $10 for 4 apples and 4 oranges. So, the first equation will be.......
![4x+4y=10 ........................................(1)](https://img.qammunity.org/2020/formulas/mathematics/high-school/kdhlt49f7r2snqfi17vl4b5xiynhj5uxww.png)
They also need $15 for 6 apples and 6 oranges. So, the second equation will be........
![6x+6y= 15 ........................................(2)](https://img.qammunity.org/2020/formulas/mathematics/high-school/apq27k8ehkbxr5wfg814bv5z18qq0l96zd.png)
Dividing equation (1) by 2 on both sides :
![2x+2y= 5](https://img.qammunity.org/2020/formulas/mathematics/high-school/kiemomvgi94cv1y3tfre30ikk8gcmbm4s1.png)
Dividing equation (2) by 3 on both sides :
![2x+2y=5](https://img.qammunity.org/2020/formulas/mathematics/high-school/2yhnyibhl2bv6nnfuqchecmshn7oaspq08.png)
So, we can see that both equation (1) and (2) are actually same. That means, we will not get any unique solution for
and
here. Both
and
have "infinitely many solutions".
Thus, we can't find a unique price for an apple and an orange.