Answer:
43/7
(x - 6)^-1 + 6
Step-by-step explanation:
inverse of 13 is such u that
u [+] 13 = 7
so
13u - 6(u + 13) + 42 = 7
7u - 78 + 42 = 7
7u - 36 = 7
7u = 43
u = 43/7
We could also simply do
[-]13 = -1[*]13 = (13-6)^-1 + 6 = 1/7 + 6 = 43/7
We see that the second method is much easier.
[-]x = -1[*]x = (x - 6)^-1 + 6
