The given function is f(x) = 3x7 + 4x + 19.
To find f(-7), we substitute -7 for x in the function.
Substituting -7 for x, we get:
9-7) =3(-7)2+4(-7)+19
Now, let's simplify the expression step-by-step:
First, we square -7:
（-7）3=（-7）*（-7）=49
Next, we multiply 3 by 49:
3 * 49 = 147
Then, we multiply 4 by -7:
4* (-7) = -28
Finally, we add up the terms:
f(-7) = 147 + (-28) + 19
Now, we can simplify further:
147 + (-28) + 19 = 147 - 28 + 19 = 138
Therefore, f(-7) is equal to 138.