Answer:
Simply
1 - x = 16 - 4x when the x is 5:
Substitute x for 5, by replacing x with 5.
1 - (5) = 16 - 4(5)
1 - 5 = 16 - (4 * 5)
1 - 5 = 16 - 20
-4 = -4
LHS - RHS
It is better to show this by doing each side individually - Left Hand Side (LHS) and Right Hand Side (RHS).
LHS
1 - x when x = 5
1 - 5 = -4
RHS
16 - 4x when x = 5
16 - 4(5) = 16 - 20 = -4
