Remember some basic rules

and
![x^ \frac{m}{n}= \sqrt[n]{x^m}](https://tex.z-dn.net/?f=x%5E%20%5Cfrac%7Bm%7D%7Bn%7D%3D%20%5Csqrt%5Bn%5D%7Bx%5Em%7D%20%20)
so

1/2-2/7=
7/14-4/14=
3/14

Answer:
Infinite Solutions
Step-by-step explanation:
x + y = 4
y = -x + 4
x + y = 4
x - x + 4 = 4
0 = 0
The difference between the flat fees of the two companies is $20
The Square Root of 245 is 15.65 (rounded to 2 dec. Places)