Let

If f(x) is a function which is continuous everywhere, then we must have
m=________________

I am not sure what m is supposed to mean. Can you define m?

Sorry, I had problems posting all these questions...

Let

f(x) = mx-12 if x is less than -5
fr(x)= x^2 +5x -7 if x is greater than or equal to -5.

If f(x) is a function which is continuous everywhere, then we must have
m=_______

To determine the value of m when f(x) is a function that is continuous everywhere, we need more information or context. The equation you provided does not offer enough details to find a specific value for m.

However, in general, the continuity of a function at a specific point depends on the limit as x approaches that point. For example, if f(x) is continuous at x = a, then the limit of f(x) as x approaches a from the left (denoted as f(a-) or lim(x→a-) f(x)) must be equal to the limit of f(x) as x approaches a from the right (denoted as f(a+) or lim(x→a+) f(x)), and those limits must also be equal to f(a).

Therefore, in order to fully determine the value of m, additional information or context regarding the specific function f(x) or the equation involving m is needed.