1 ÷ 0 is undefined. nothing can be divided by 0.
Answer:

Step-by-step explanation:
Given that,
The frequency of x-rays, 
We need to find the wavelength for x-rays. The relation between wavelength, frequency and speed of light is given by :

So, the wavelength for x-rays is
.
Step-by-step explanation:
9x - 2x = 8 + 5
7x = 13
x =13÷7
x = 1.8571
approximately = 1.86
I think this is it
11x = -7y
this is the answer because you combine the x together