For each value of u, determine whether it is a solution, u/7 +1=7 28, yes or no? -49, yes or no? 42, yes or no? 0, yes or no?

Given u/7 - 1 = 7 and plugging in values for u,

For u = 28; 28/7 - 1 = 4 - 1 = 3; No
For u = -49; -49/7 - 1 = -7 - 1 = -8; No
For u = 42; 42/7 - 1 = 6 - 1 = 5; No
For u = 0; 0/7 - 1 = -1; No

Another way to find out which value would be a solution to u/7 - 1 = 7 is to solve for u.

u/7 - 1 = 7
u/7 = 7 + 1
u/7 = 8
u = 8*7
u = 56

The only solution to this equation is when u = 56.