Let f(x) represent a function.
When any number is added or subtracted with f(x) at the end , then f(x) is translated up or down
f(x) + a --> f(x) is translated 'a' units up
f(x) - a --> f(x) is translated 'a' units down
f(x) - 4 -->f(x) is translated 4 units down
When any number is multiplied with f(x), then f(x) is stretches or compress vertically
f(x) --> 4 > 1, f(x) vertically stretched by a factor of 4