Evaluate using the functions f(x) = 3x–8 and g(x) = -x2+ 4x–11.
1 . f(10+10
2. g(-9)+7
3. -2xg(4)
4. f(-4)-g(7)
5. Given f(x)= 9 –2x, if f(x)= 19, find the value of x.