If f (x) = x^2 and g (x) = 4f (x) - 1, then what is the value of g (-3) ? I don't get it ...

The answer is 35.

For g (-3), we substitute - 3 for x:

g (-3) = 4f (-3) - 1

Since f (x) = x², this means that

f (-3) = (-3) ² = 9; we can put this in place of f (-3):

g (-3) = 4 (9) - 1

g (-3) = 36 - 1 = 35