Fthere are 12 fish and half of them drown, how many are there?

Step-by-step explanation:

f(4) = 42 + 5 =21, f(-10) = (-10)2 +5 = 105 or alternatively f: x → x2 + 5.

The phrase "y is a function of x" means that the value of y depends upon the value of x, so:

y can be written in terms of x (e.g. y = 3x ).

If f(x) = 3x, and y is a function of x (i.e. y = f(x) ), then the value of y when x is 4 is f(4), which is found by replacing x"s by 4"s .

If f(x) = 3x + 4, find f(5) and f(x + 1).

f(5) = 3(5) + 4 = 19

f(x + 1) = 3(x + 1) + 4 = 3x + 7